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The Messy Mediterranean

August 11, 2020
Marissa Wood

Or, Why is Mediterranean Maritime Sovereignty So Complicated?

The Mediterranean Sea could almost be considered an inland body of water, except for a small connection to the Atlantic Ocean (only 16 km or 10 miles) between the coasts of Spain and Morocco at the Strait of Gibraltar. The waters of the Mediterranean can be further divided into the Alboran, Libyan, Levantine, Aegean, Ionian, Adriatic, Tyrrhenian, and Balearic Seas. Twenty-three separate States lay claim to the waters of the Mediterranean Sea, and many of these are overlapping or disputed leading to an incredibly complex picture of maritime sovereignty.

The Established Boundaries

There are, however, twenty-two established maritime boundaries between the various Mediterranean States. The oldest is between Cyprus and the UK on behalf of its Sovereign Base Areas (SBAs) of Akrotiri and Dhekelia located in the south of the island. Both the land and maritime boundaries between the SBAs and Cyprus were established by the same agreement from which Cyprus gained its independence from the UK on 16 August 1960. The maritime boundary extends in four separate parts from the various land boundary termini on the coast and delimits the UK’s claimed three nautical mile territorial sea and Cyprus’s 12. The UK ceded all exclusive economic zone (EEZ) claims to Cyprus.

Map showing the maritime boundary between Cyprus and the UK Sovereign Base Areas of Akrotiri and Dhekelia.
The four-part Cyprus–UK maritime boundaries.

The most recent (as of late July 2020) Mediterranean maritime boundary is between Greece and Italy, signed on 9 June 2020. This new agreement updates a 24 May 1977 Treaty, transforming the already-established 16 point maritime boundary into WGS-84 and confirming its application for the EEZ, in addition to the continental shelf (CS). The 2020 update left the tripoints, with Albania in the north and Libya in the south, undefined. The Italy–Greece boundary is arguably less interesting than the second most recent Mediterranean maritime boundary between Turkey and Libya (signed 27 November 2019). That will be covered in greater depth below.

A map depicting the maritime boundary between Greece and Italy.
Greece and Italy’s original 1977 maritime boundary was updated to WGS-84 in 2020.

If you’re interested in learning more about the maritime boundary between Greece and Italy, check out our Boundaries page.

Surprise! Greece and Egypt signed a new EEZ boundary Agreement on Thursday, August 6. The details have not yet been released to the public, but both Turkey and Libya have already protested the new boundary.

The shortest established Mediterranean maritime boundary is between Italy and Slovenia at 15 M and the longest is between Italy and Tunisia, which runs for 528 M.

That leaves about 30 maritime boundaries to be established, some of which are currently being negotiated (Greece and Albania) and some of which have 300 plus years of dispute that will need to be resolved before maritime boundary delimitation can begin (Spain and the UK on behalf of Gibraltar).

Disputed Maritime Space

When looking at disputed maritime areas in the Mediterranean, Turkey is the shadow over all of the eastern Sea. Its role in the Cyprus–Northern Cyprus conflict as well as the full extent of maritime disputes with Greece will be discussed in greater detail below. This section is to delve into Turkey’s full set of unilateral maritime claims which were updated in 2019.

Map showing the various established maritime boundaries as well as claims.
Unilateral maritime boundary claims and provisional equidistance divisions create a messy picture of potential sovereignty in the eastern Mediterranean. The full extension of Turkey’s EEZ claims is based on a 2019 map published by this news source.

Additionally, on 27 November 2019, Turkey and the UN-backed government of Libya (Libya is in the midst of a civil war, so yes, there are two entirely separate governments) signed a short, two-point maritime boundary agreement that dangles in the middle of Greek-claimed sea. This new boundary enraged neighboring Greece and Egypt as well as the entire EU. Its location deviates from the equidistance default stipulated by UNCLOS. Turkey and Libya note that the bilaterally negotiated boundary has nothing to do with third states, but as Greece claims the waters surrounding this new delimitation, it has caused quite a stir. The new August 2020 Egypt–Greece maritime boundary likely overlaps with the Libya–Turkey boundary in some capacity.

The conflict between Cyprus and Northern Cyprus would not have reached its modern outcome without Turkish involvement. Disagreements between Turkish Cypriots and Greek Cypriots on the island of Cyprus have been ongoing since even before Ottoman control of the island, and the modern conflict began shortly after independence from the United Kingdom. Turkey moved to occupy northern Cyprus in 1974 and the Turkish Republic of Northern Cyprus declared independence in 1983. Today, Turkey is the only country who recognizes Northern Cyprus’s statehood.

The island of Cyprus is now divided by a UN mandated and monitored buffer zone that snakes its way through hilly territory and divides the capital city (for both Cypruses) of Nicosia. The southern Greek Republic of Cyprus is an EU member and is recognized by the UN as the sole sovereign power of the island.

Related to the Cyprus dispute, the maritime picture off the coast of the island is quite complicated. The Republic of Cyprus has established maritime boundaries with Egypt, Israel, and Lebanon, in addition to the short UK boundaries already mentioned. Northern Cyprus agreed to a maritime boundary with Turkey, that the southern Republic of Cyprus disputes. Due to the nature of the dispute, the maritime boundaries between Cyprus and Northern Cyprus are also unresolved (and unlikely to become so in the foreseeable future).

Turning to the maritime disputes between Turkey and neighboring Greece offers an even more complicated picture (at least delimitation wise) due to the multitude of Greek Islands that lay just off the Turkish coast. Relations between Turkey and Greece have been historically complicated and often quite problematic, negativity driven by both the conflict in Cyprus and unresolved maritime issues in the Aegean Sea. Oil was discovered in the continental shelf in 1973, adding [literal] fuel to the fire.

Greece and Turkey have two extremely different perspectives on the possible delimitations of the maritime boundary through the Aegean Sea. Turkey is not a signatory of UNCLOS and claims that Greece’s Aegean Islands are not entitled to full continental shelf claims and would seek to have a mainland coast equidistance boundary through the middle of the Aegean Sea, while enclaving the Greek islands on the Turkish side of the maritime boundary line. Greece, a signatory of UNCLOS, meanwhile proposes a strict equidistance-based maritime boundary utilizing all of its islands, pushing the maritime boundary far to the east, just off the Turkish coast. Turkey’s position on the Greek claim is that this would create a “Greek Lake” of the Aegean Sea and severely limit Turkey’s freedom of navigation from the Black Sea to the Mediterranean.

There is also at least one officially disputed island between Turkey and Greece known as Imia by the Greeks and Kardak by the Turks. Turkish claims to additional islands have been made and redacted over the years.

Conflict over Greek and Turkish maritime claims is common. During the summer of 2020, Turkey has been conducting seismic surveys in Greek-claimed waters. And Greece is working on increasing its military power in response to Turkish aggression. Meanwhile, diplomats from the two states also sat down for a round of negotiations. In August, Greece called for talks to continue or a referral of the dispute to the ICJ. To read more, check out this article.

Looking beyond Turkey-centered disputes, there is a handful of interesting and impossible to resolve conflicts that speckle the entire Mediterranean Sea and neighboring bodies of water. Israel and Lebanon seem to be constantly in conflict over both their unresolved land boundary and maritime frontier. Natural gas reserves have been discovered in maritime space that both states claim, and in 2018 Lebanon auctioned off several disputed oil blocks. Israel is currently working on its own oil exploration in the disputed area.

The Palestinian territory of Gaza set forth maritime claims in 2015 and 2019 in which they proposed lateral boundaries with Egypt and Israel, creating a corridor of Palestinian maritime space before reaching the boundary with Cyprus. Both Israel and Egypt have submitted protests to the UN over Palestine’s unilateral maritime claims.

A map showing Palestine's unilateral maritime claims (a corridor from Gaza Strip to the already established boundaries with Cyprus).
Palestine’s unilateral maritime claims extend from the Gaza Strip out to the already established boundaries with Cyprus.

The former Yugoslav States of Croatia and Slovenia also have disputed maritime space in the northern Adriatic Sea despite a 2017 Permanent Court of Arbitration Award delimiting the boundary (Croatia had unilaterally withdrawn from the case in 2015 following a scandal). Slovenia accepts the Tribunal’s delimitation, but Croatia does not.

Some similarities can be drawn to the maritime boundary between Greece and Albania in the southern reaches of the Adriatic Sea. The two States signed a maritime boundary agreement in 2009, but this document was annulled shortly thereafter by Albania. Negotiations over the maritime boundary began again in 2018 and are ongoing. And with Greece’s current dedication to maritime boundary delimitation with its neighbors it is plausible that a new Greece–Albania maritime boundary Agreement could be signed in the coming months.

The remaining maritime disputes in the western Mediterranean, which stem from disputed land boundaries and sovereignty claims, are quite similar (although Spain wouldn’t have you think so). I’ve briefly discussed the UK–Spain conflict over Gibraltar in this blog, and Kevin went into great depth on the dispute between Spain and Morocco over the Plazas de Soberanía, Spanish controlled enclaves claimed by Morocco. Each island or small territory, Perejil Island, Ceuta, Peñón de Velez de la Gomera, Islas Alhucaimas, Melilla, and Islas Chafarinas, all yield a strange smattering of Spanish maritime enclaves within Moroccan-claimed waters, making for quite the sovereignty mess in the western Mediterranean.

The possibilities of maritime sovereignty in the Mediterranean Sea are incredibly complicated with many neighboring states diametrically opposed to compromise. The potential for oil and natural gas in the eastern Mediterranean has created a high stakes scenario that could spark conflict between interested parties. While some states are actively involved in negotiations, it seems more likely that the potential maritime boundaries of the Mediterranean will get messier before a coherent picture of sovereignty is established.

The Strange Boundaries of Equatorial Guinea

March 2, 2020
Marissa Wood


Equatorial Guinea is a small central African state that is made up of a series of islands and a mainland territory. The islands are spread out throughout the eastern Gulf of Guinea, the largest of which is Bioko, located just off the coast of Cameroon, followed by Annobón to the southwest of São Tomé and Príncipe, and then Corisco and Elobey Islands located closer to the mainland. Continental Equatorial Guinea is referred to as Río Muni.

An overview map of Equatorial Guinea, showing both its continental territory known as Rio Muni along with its islands of Bioko and Annobon.
Equatorial Guinea extends beyond continental Río Muni. It also consists of Bioko, Annobón, and several smaller islands.

The modern-day African state was formerly a loosely controlled Spanish colony before gaining independence in 1968. If you’re interested in colonial Equatorial Guinea, this article gives an excellent overview. Since its independence, Equatorial Guinea has become infamous for being one of the most corrupt and repressive states in Africa, with the current president serving as Africa’s longest running dictator. Equatorial Guinea struck offshore oil wealth in the mid-1990s, and despite the economic boom, the majority of Equatorial Guineans live in abject poverty. To learn more about Equatorial Guinea’s current political status, The Guardian had some great recent coverage.

Mainland Equatorial Guinea shares land frontiers with only Cameroon and Gabon, but its various islands have both established and provisional maritime boundaries with Cameroon, Nigeria, São Tomé and Príncipe, and Gabon. Both of its land borders have differing de jure (legal) versus de facto (actual) practices, and only two of its potential maritime boundaries have been established (with Nigeria and São Tomé and Príncipe).

Land Boundaries

The land boundary between Río Muni and Cameroon was defined in vague terms between French and German colonial powers in 1885. Interestingly, Spain had such a minute presence in mainland Equatorial Guinea that France was able to claim Río Muni in its “spheres of influence” agreement. Germany at the time administered Cameroon. France would officially relinquish its claims to Río Muni in 1900. The 1885 Agreement also separated French and German claims in west Africa, including between modern-day Benin and Togo, and authorized French control of Senegal and the Gambia.

Map showing the land boundary between Equatorial Guinea and Cameroon
The 1885 land boundary extends from the Atlantic Ocean to the tripoint with Gabon. Note the de jure/de facto differences in the line.

The boundary between German Kamerun and Río Muni as defined in 1885 followed the Campo or Ntem River from its mouth in the Bight of Biafra until the river meets the 10˚ East meridian and from there the borderline is “the parallel of latitude” (no additional descriptors offered) until the 15˚ East meridian, after which French and German claims in 1885 dissolved into unknown jungle. Neither Spain and Germany, nor Spain and France, or even modern-day Equatorial Guinea and Cameroon have signed any additional boundary agreements.

Modern-day administrative practices differ from the 1885 delimitation in a few key places. First, the Campo/Ntem River is utilized as the boundary line past the 10˚ East meridian until the river takes a sharp turn to the north into Cameroon. The unspecified parallel of latitude serves as the boundary except for a slight northward deviation to the west of the Equatorial Guinean town of Ebebyín. The differences in de jure/de facto practices are not currently the source of any official boundary disputes, although Cameroon has complained at times of Equatorial Guinea’s unilateral border fencing encroaching on Cameroonian territory. The frontier desperately needs a modern demarcation but lack of funds, lack of motivation, and the likely difficulties in resolving de jure/de facto differences have stalled this process.

Equatorial Guinea’s other land boundary is similarly problematic. In the same 1900 agreement in which France officially relinquished its claim to Río Muni to Spain, a vague frontier was defined with then French Congo, modern-day Gabon. It begins in the mouth of the Muni River in the Bight of Biafra and continues along its thalweg to the Outemboni River until it first meets the 1˚ North parallel, which it then follows until the 11˚20’ East meridian which serves as the border northward until it meets the frontiers of Cameroon.

Map showing the land boundary between Equatorial Guinea and Gabon.
The 1900 land boundary between Equatorial Guinea and Gabon. Note the differences in de jure versus de facto control.

Of course, this de jure description only partially captures the story. The river boundary is utilized further to the east of its first meeting with the 1˚ North parallel, the de facto boundary extends to the north of the parallel to allow for Gabonese control of the town of Médouneu, and the Kié River functions as the operative boundary to the tripoint with Cameroon, so that the entire town of Ebebyín is administered by Equatorial Guinea.

As a brief aside, the de jure boundary versus de facto control over the town of Médouneu has been handled cartographically in a variety of ways by major web map providers. Google has proffered the most interesting solution, placing their Médouneu label on the 1˚ North boundary, when the actual town, in fact, lies to the north based on the distribution of populated places in satellite imagery. It can be frustrating when the facts on paper don’t match the facts on the ground.

Screenshot of Google Imagery showing how Médouneu is labeled below the 1 degree parallel boundary when in fact the city is to the north.
The location of Médouneu on a screenshot from Google Maps.

A Modern Frontier Delimitation?

The boundaries between Equatorial Guinea and Gabon get weirder. In 2004, Gabon submitted what it claimed to be a 1974 bilateral agreement on land and maritime frontiers with Equatorial Guinea to the United Nations. Article 2 of this agreement contains adjustments from the 1900 colonial delimitation which better adhere to current de facto practices. It also grants a series of disputed islands, Mbanié, Conga, and Cocoteros, to Gabon and defines a maritime boundary.

Fifteen days after Gabon’s submission of the 1974 agreement to the UN, Equatorial Guinea presented its first objection which was followed by two additional notes expressing concern over the validity of the agreement. Equatorial Guinea commented on the lack of original signed French and Spanish copies of the 1974 text. Additionally, despite supposedly signing an agreement, the two states continued bilateral maritime boundary negotiations from 1972 to the present. Equatorial Guinea considers the 1974 agreement a forgery with no legal basis in the definition of its land and maritime frontiers with Gabon.

In 2016, Equatorial Guinea and Gabon agreed to submit their maritime dispute to the International Court of Justice. The land boundary issues do not seem to have been included in this initial framework. Equatorial Guinea ratified the agreement in 2017, but Gabon has yet to do so and the ICJ has not been presented with the case.

Maritime Boundaries

In addition to Equatorial Guinea’s rather strange land boundaries, it has two established maritime boundaries, one in the north between Bioko and mainland Nigeria, two separate segments of boundary with São Tomé and Príncipe, one for Bioko and one for Annobón. The maritime boundary with Nigeria was established in a 2000 agreement after a decade of negotiations for which oil exploitation was a key driver. The two-part maritime boundary with São Tomé and Príncipe was established based on the principle of equidistance in 1999. None of the four potential tripoints have been officially established.

Map showing the maritime boundary between Equatorial Guinea and Nigeria
The maritime boundary between Bioko and Nigeria.

Equatorial Guinea has yet to establish an official maritime boundary with Cameroon, although the two states are in negotiations. Potential boundary delimitations with Gabon are further complicated due to the dispute over Mbanié, Conga, and Cocoteros Islands. The maritime frontier with Gabon will have a northern segment dividing the adjacent coasts of Río Muni and Gabon and a western segment for the opposite costs of Annobón Island and Gabon.

Map showing the maritime boundary between Equatorial Guinea and São Tomé and Príncipe
The maritime boundary between São Tomé and Príncipe and Annobón in the south and Río Muni and Bioko in the north.

There is much work to be done on the international land and maritime boundaries of Equatorial Guinea. The presence of hydrocarbons has driven negotiations and the establishment of maritime frontiers with São Tomé and Príncipe and Nigeria. But sorting out overlapping maritime claims and vague colonial delimitations with Cameroon and Gabon is much more complicated. In both those cases, at the minimum, a modern, complete, and bilaterally agreeable land boundary needs to be established before any real maritime negotiations can occur. A thorough demarcation would be better. This may be possible with Cameroon in the short term but is much more complicated with Gabon due to the more contentious de jure/de facto boundary issues and the dispute over Mbanié, Conga, and Cocoteros. Without an economic driver, it may be a very long time before Equatorial Guinea’s boundaries are more firmly located than those drawn up during the colonial period on old, small scale, and inaccurate maps.

A Primer on Boundary Disputes

December 1, 2019
Marissa Wood

International boundary disputes, both on land and at sea, have been a particular focus of mine for the past few months. At the end of the year, we are unveiling our “Disputed or Contentious Sovereignty” collection of annotated points in the Sovereign Limits web research portal, and in October, I presented on boundary disputes for the 2019 NACIS (North American Cartographic Information Society for non-map nerds) conference in Tacoma, Washington. This blog provides an initial overview on how we at International Mapping monitor and maintain boundary disputes. 

Map of the world showing hundreds of small red dots marking areas of disputed or contentious sovereignty.
Sovereign Limits “Disputed or Contentious Sovereignty” point layer.


Boundary disputes come in many forms and are therefore somewhat complicated to count and catalog. From the outset, Sovereign Limits has kept track of disputes where two states have clearly defined opposing claim lines on land or over sovereignty of islands. But these account for only 74% of all of the disputes we maintain records on. The rest fall under our category of “contentious” sovereignty. This intentionally vague label has allowed us to broaden our definition of disputes to monitor less clear-cut but still important conflicted areas.

Areas of contentious sovereignty include, for example, the dispute between Afghanistan and Pakistan, where Afghanistan disputes the British colonially imposed boundary, known as the Durand Line, but it does not offer an alternative claim of its own. Rather, Afghanistan would like to renegotiate the entire frontier with Pakistan, since both states are now on more equal political footing than they were in 1893 when the Durand Line was initially delimited (Pakistan, then part of British India, had the backing of all of the United Kingdom’s technical prowess, military strength, and knowledge of how to create frontiers with the express purpose of undermining the localities they were occupying; meanwhile Afghanistan struggled at the negotiating table and fought to maintain its independence at the cost of territory and a manageable boundary).

Afghanistan in 1893. Map from the Library of Congress.

Contentious sovereignty also includes maritime disputes over features that can or cannot be utilized to generate an exclusive economic zone (EEZ). Some notable examples in this category include Spain’s dispute over Portugal’s use of the Savage Islands to generate an EEZ, or China, South Korea, and Taiwan all disputing Japan’s use of Okinotorishima Atoll in the same manner. 

Cool Stats

With those definitions in mind, we maintain a database of disputed and contentious sovereignty for Sovereign Limits that includes about 200 individual locations. The state with the most of these is China with about 30 places of disputed or contentious sovereignty, ranging from high profile territorial conflicts with India to lesser known areas of contention with North Korea.

The largest dispute, where the most territory is at stake by area, excluding maritime space, is between Morocco and Western Sahara. The second largest land dispute is between Somalia and Somaliland. It is interesting that the top two in this category are similar separatist territories claiming their own independence from the state to which they have historically been a part of.

Showing Western Sahara as disputed territory, and Moroccos line of control almost all the way to the southern border with Mauritania.
Map showing the disputed boundary(ies) of Western Sahara. Morocco maintains control of territory up to the dotted line, which is actually made up of sand berms visible in satellite imagery.

Once you include maritime space, where competing states can claim 200 nautical mile EEZs from their coastlines, the picture shifts. The dispute between Argentina and the United Kingdom over South Georgia and South Sandwich Islands generates the greatest potential maritime space at over 1,431,000 square kilometers. It’s followed by the United Kingdom’s dispute with Mauritius over the Chagos Archipelago in the Indian Ocean. Western Sahara still comes in third when maritime space is taken into account for total area disputed.

The smallest dispute by area is between Croatia and Slovenia over a tiny plot of land referred to as Area 9.4 by Croatia and part of the Prezid series of disputes. It has an area of only 1.7 acres (just a little bit bigger than my suburban yard…). Interestingly, the seven smallest disputes in Sovereign Limits are all between Croatia and Slovenia and are still contested despite a 2017 Award issued by the Permanent Court of Arbitration (Croatia unilaterally withdrew in 2016 and does not recognize the Award). In addition to these seven smallest, there are five more disputed areas between Croatia and Slovenia, for a total of eleven, including one over the location of the maritime boundary in Piran or Savudrijska Bay. Furthermore, Croatia has disputes with all of its neighbors except Hungary. For more information on why this is, check out my blog on the Balkans.

Top: large scale map of the 1.7 acre Prezid dispute
Bottom: Balkans regional map featuring Croatia's disputes
Croatia and Slovenia disputes featuring tiny Prezid.

I could spend the rest of my life writing about boundary disputes and never explore them all. Sometimes disputes are resolved, and there are always more to add. I’ve written about a few of so far for the Sovereign Limits blog (the post on Egypt and Sudan has it all with terra nullius, bad colonial boundaries, and high stakes maritime space) and will continue adding to the list. If this is something that interests you, please check out my NACIS talk, where I go into some additional details about some of the most interesting (to me) international boundary disputes.

Egypt–Sudan Land Boundary

July 31, 2019
Marissa Wood
The land boundary between Egypt and Sudan

At first blush, the land boundary between Egypt and Sudan is fairly simple, it runs from west to east along the 22˚ North parallel. But looking closer 32% of its length is actually in dispute, with Sudan claiming a boundary based on a different set of colonial documents.

All variations of the modern international boundary between Egypt and Sudan were established under the influence of, or direct administration by, British colonial authorities. The UK gained control over Egypt from the Ottoman Empire in the late 19th century. Egypt was never an official colony of the UK, but it wasn’t fully independent until after the Egyptian Revolution in 1953. Sudan was co-administered by British and Egyptian officials until its independence in 1956.

There are three areas in dispute between Egypt and Sudan: Wadi Halfa, Bir Tawil, and the Hala’ib Triangle. Egypt claims and has de facto control of all of the territory north of the 22˚ parallel as initially established as the international boundary in a 19 January 1899 Agreement as Egypt and the UK sought to reassert their authority and joint administration over Sudan. Over the next eight years, documents would be issued by colonial administrators adjusting or supplementing the initial boundary, and it is from these that Sudan’s claims stem.

Wadi Halfa: A Dispute Under Water

The first dispute, geographically and temporally, is 650 km east of the tripoint with Libya and is commonly referred to as Wadi Halfa. The dispute itself actually lies 28 km north of the Sudanese Town of Wadi Halfa and today is almost completely submerged beneath Lake Nasser. On 26 March 1899, an arrêté was made adjusting the 22˚ North parallel boundary in the vicinity of Wadi Halfa. Instead of crossing the Nile River along the line of latitude, the government officials recommended a deviation to the north, placing several towns within Sudan.

The northward jut of the revised boundary around Wadi Halfa is now almost entirely beneath the shores of Lake Nasser (known as Lake Nubia in Sudan). In 1960, construction of a dam near the town of Aswan, Egypt began, and today the filled reservoir provides water and irrigation to Sudan and Egypt.

The status of the 1899 Arrêté, and subsequent reaffirmation in 1907, is often considered de jure. These documents were intended to adjust an international boundary. Egypt disputes this assessment, however.

The adjustment to the boundary near Wadi Halfa on a 1942 Sudanese map, corresponding with Sudan’s modern claim.
The adjustment to the boundary near Wadi Halfa on modern imagery showing the flooding of the Nile River.

Bir Tawil and the Myth of Terra Nullius

Technically, neither State currently lays claim to Bir Tawil. But it is also not “terra nullius” (an area of land claimed by no state) because Sudan and Egypt assign it to the other country based on their claim lines. Bir Tawil lies south of the 22˚ North Parallel, so Egypt can’t claim it; they instead “give” it to Sudan. Bir Tawil does not fall within the adjustments to the tribal boundaries, so Sudan can’t claim it, and they “give” it to Egypt. Because it is a remote, unpopulated desert, neither State makes any effort to maintain de facto control over the area.

But many like to argue in favor of terra nullius for Bir Tawil. It is sensational and an interesting exercise to think outside the realm of established international boundaries and all of the modern geopolitics and historical context. In 2014, an American laid claim to Bir Tawil so that his daughter could be a princess and dealt with a massive international backlash. If this story interests you, The Guardian produced an excellent and in depth piece on the dispute, or lack there of, over Bir Tawil.

High Stakes Hala’ib Triangle

The bread and butter of the Egypt–Sudan dispute is over the Hala’ib Triangle. While it is still remote and desert, it is populated, and has natural resources, including gold and oil. Through Bir Tawil and the Hala’ib Triangle, Egypt claims the boundary along the 22˚ North parallel based on the January 1899 Agreement. Sudan’s claim stems from a 4 November 1902 Arrêté that provided for a boundary adjustment or an additional administrative boundary, depending on your perspective, to allow for colonial authorities to more effectively manage the movement of nomadic tribes. Needless to say, the nomadic groups of the early 20th century were less interested in a convenient straight line boundary than they were over access to grazing lands and water that they had historically utilized.

There was almost a full scale conflict between Egypt and Sudan over the Hala’ib Triangle during the 1950s when Sudan set it up as an electoral unit. After Egypt’s withdrawal of troops, the dispute then remained dormant until 1992 when Sudan granted drilling rights to a Canadian oil company. In response, Egypt unilaterally annexed the Hala’ib Triangle and has maintained de facto control of it since.

Egypt’s claim to the Hala’ib Triangle. Note that they “give” Bir Tawil to Sudan based on their claim line.
Sudan’s claim to the Halai’b Triangle. Note that they “give” Bir Tawil to Egypt based on their claim line. In neither scenario is Bir Tawil terra nullius.

The Role of the Red Sea

Stakes over the Hala’ib Triangle grew as oil and natural gas exploration occurred in the Red Sea. The maritime area in dispute off shore of the Hala’ib Triangle is larger than the land territory in conflict and potentially richer in natural resources. In 2016, Egypt and Saudi Arabia signed a maritime boundary Agreement in the Red Sea that extends into the disputed area. Sudan lodged a protest with the United Nations, noting that points 55 through 61 of the Egypt–Saudi Arabia maritime boundary infringe on Sudanese maritime space.

The maritime area in dispute between Egypt and Sudan offshore of the Hala’ib Triangle.

The territory dispute between Egypt and Sudan has existed since colonial times and resolution seems to be no closer now than it was then. Relations between the two States are complex and often tense, though recently there have been bilateral efforts to work together to resolve water usage issues of the Nile River and the boundary dispute itself.

Top 3 Boundaries to Visit

April 30, 2019
Marissa Wood

For several years, I spent most of my working days drawing boundaries. I’d follow along watersheds in a digital elevation model (DEM) or a visible ridge in a properly georectified image. Others, I’d trace along the middle of a river, wondering what it was like for the people living on the shore. And on some lucky days, I could connect demarcation pillars or monuments visible in satellite imagery (that was the best because it meant I knew exactly where the boundary was supposed to go). In all my imaginary travels along international boundaries through large-scale imagery, I would let my mind wander, thinking about what it would be like to actually visit or live in this city split between two States, or on this beach with waves lapping at a land boundary terminus pillar.

I love to travel, and I want to go everywhere. There are very few land boundaries that I’ve worked on where I thought, “No I wouldn’t want to visit this place.” And even for those, I could pick out more than a few positives if presented with an opportunity to see them. It was easy to choose my top boundary to visit but much harder to select another two from my never-ending list of places I’d like to see. I have a whole tab on my personal travel wish list labeled “boundary tourism.”

No. 1: Mt. Roraima, the Brazil–Guyana–Venezuela Tripoint

Hikers follow a trail far below the touring plateau of Mt. Roraima.
The hike to Mt. Roraima (from kimkim’s tours).

This was my first entry, way back in 2014, when Sovereign Limits was a yet-unnamed project I was working on in my spare time. Mt. Roraima towers 400 m (1,300 ft) over the surrounding plains in the Guiana Highlands, and, as a distinctive geographical feature, it has been used since the 19th century by colonial surveyors as a reference point for the various abutting boundaries and probably by indigenous peoples before. While it was monumented, likely sometime in the 1930s, there was never an official trilateral Agreement between Brazil, Guyana, and Venezuela, or their colonial administrators, because Venezuela has intermittently disputed the location of the tripoint. It is currently in conflict, and Guyana has brought a case before the ICJ over their entire land and maritime frontiers with Venezuela (Venezuela claims about half of Guyana, up to the Essequibo River).

The tripoint is located on the plateau, somewhere along the watershed at its peak. It is very difficult to precisely determine the location of this tripoint since coordinates are not available in a modern datum and the plateau has received some very interesting and sometimes conflicting georectifications depending on the image source, leaving potential locations for the tripoint as much as 250 m (820 ft) away from each other.

But there are guided, pack in, pack out hiking/camping trips to Mt. Roraima, all of which feature pictures with the tripoint as an adventure highlight. There are also epic waterfalls and views, but really, it’s all about the tripoint, right? It’s supposed to be one of the best hikes in Venezuela. How could you not want to visit such a breathtaking mountain? And how could I resist the temptation to scramble up with a Trimble or some other precise GPS unit and take my own coordinates in WGS-84 and get that tripoint on the map exactly where it belongs, dispute or no dispute?

Hikers sit at the base of the tripoint among craggy rock features.
The dispute Brazil–Guyana–Venezuela Tripoint (from kimkim’s tours).
Shaded relief map of Mt. Roraima showing the international boundaries
Boundary map in the vicinity of Mt. Roraima.

No. 2 Belgium–Netherlands Land Boundary

Belgium has some very neat boundaries. In addition to the funkiness with the Netherlands discussed in greater detail below, Belgium also has some weird German enclaves created by an old rail line, the Vennbahn, that has since been converted to a bike trail that I will someday ride through.

But even more, I want to visit Baarle-Hertog, a Belgian enclave in the Netherlands’ town of Baarle-Nassau. Baarle-Hertog is a series of enclaves nested within one another like a donut hole in a donut on a plate or, perhaps more fitting, a wheel of Dutch gouda, filled with Belgian passendale, with its holes filled with Dutch edam. Cheese-ception? Maybe.

Just regular enclaves, small territories of one country fully nested within another, are weird boundary scenarios, but the international boundary between Belgium and the Netherlands is next level. Belgian Baarle-Hertog consists of 24 separate parcels, 21 of which are fully enclaved by the Netherlands. Within the two largest chunks of Baarle-Hertog are seven separate Dutch enclaves, not to mention the additional Dutch field just across the primary international boundary in Belgium. The boundary weirdness stems from medieval land exchanges but was finalized in 1995. The border is fully demarcated, even as it splits buildings and gardens. One NPR article notes that in the course of a minute of quick walking, it’s possible to cross the international boundary five times. I cannot wait to do this.

A map showing all of the enclaves associated with Baarle-Hertog. A very strange looking international boundary.
Map of the Baarle-Hertog/Baarle-Nassau enclaves.

No. 3 Gibraltar

This picture sums up the epic beauty of the Rock of Gibraltar. From Wikipedia.

Gibraltar is a place I’ve wanted to visit long before I was researching boundaries. There were epic pictures of the Rock in various middle and high school history textbooks. What a site, situated on the edge of the Mediterranean Sea and Atlantic Ocean, mirrored by another limestone pillar on the African continent at Jebel Musa in Morocco. As I began to learn more about the short, only 1.26 km (0.78 miles) disputed boundary, it edged towards the top of my must-see list.

In addition to its epic beauty, Gibraltar has a lot of strategic value, and the United Kingdom (just Great Britain at the time) gained control of it way back in the early 1700s during the War of Spanish Succession. There is a 1713 Agreement in which the Spanish king renounces all claims to Gibraltar and its fortifications to Her Britannic Majesty. Since then, there have been sieges and battles and world wars, but the UK has retained control over Gibraltar despite Spain’s continued protests.

I would like to explore Gibraltar for its beauty, the Moorish–Spanish–British history, the maze of tunnels running through the Rock, and most of all, its little boundary, which is almost entirely an airport on the British side.

Shaded relief map of Gibraltar with locality names, boundaries, and a few other point locations.
Map of Gibraltar. Spain disputes that there’s an international boundary there at all.

The exploration of international boundaries in satellite imagery and dreaming about traveling to them has been a fun aspect of my job and has provided entertainment during the monotony of tracing a riverine or watershed line. I cannot wait for my first trip to an international boundary armed with the knowledge of its history and construction.

A Brief History of the Balkans

March 29, 2019
Marissa Wood

This is something I missed growing up with US public school history. Yugoslavia? Huh? I managed to pretty successfully avoid the subject through an undergrad history degree, too. Hmm, the Balkans, is that some mountains or a peninsula or something? Finally, as a 20-something, I was tasked at International Mapping with helping out on the Croatia v. Slovenia Permanent Court of Arbitration (PCA) case. And while there was no glory or travel in the work I was doing—digitizing old topo maps—it served as a decent primer on the region and an opportunity to catch up on some missed history.

Now, after writing the reports for all of the Adriatic maritime boundaries, many of which stem directly from Yugoslavia in the 1970s (see Croatia–Italy, for example), I am obsessed with this fascinating, beautiful, and conflict-ridden region.

A Geopolitical Overview

The Balkans are complicated. Even its geographic definition is disputed, with most people preferring the term “Southeast Europe” to better define the area today. As a not-quite peninsula, the Balkans were named in the early 19th century after a mountain range in modern-day Bulgaria, which was mistakenly thought to be the dominant geographic feature of the area. Most people consider the northern border of the Balkan Peninsula to be a series of rivers, most notably the Danube. To the west of the Balkans is the Adriatic Sea, to the south the Ionian Sea, and to the east the Aegean Sea and Black Sea, making it kind of, sort of, a weirdly shaped peninsula.

The modern-day states which make up Southeast Europe are Slovenia, Croatia, Serbia, Bosnia and Herzegovina, Montenegro, Kosovo, Albania, North Macedonia, Greece, Turkey, Bulgaria, and Romania. Some of these are excluded from lists of Balkan States for geographic or political reasons (which is one reason why Southeast Europe has become the preferred term).

The political history of the Balkans is even more complicated than its geography, with major players over the centuries including the Greeks, Ottomans, the Austro–Hungarian Empire, and the Soviets. Its cultural and religious history is even more difficult. Today, the region is not known for its peace and stability. To examine just a small portion of time and geography, I will be focusing on how Yugoslavia came to be and then not be.

The region known as the Balkans

Yugoslavia 101

Yugoslavia was born after World War I from remnants of the Austro–Hungarian Empire in Southeast Europe, with the union of the Kingdom of Serbs, Croats, and Slovenes. In 1929, the state was renamed the Kingdom of Yugoslavia.

the Balkans before the existence of Yugoslavia

And then World War II happened. Yugoslavia was invaded by the Axis Powers. Cue several puppet regimes, Soviet control, and the eventual rise of Josip Broz Tito who would hold together Yugoslavia from 1945 until his death in 1980. While Tito modeled the new Socialist Federal Republic of Yugoslavia (SFRY) after the Soviet Union, he would eventually fall out with Stalin, and communism in Yugoslavia would take on its own unique form.

Within the SFRY were the Socialist Republics of Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Macedonia, and Serbia. The SR of Serbia included two semi-autonomous provinces: Vojvodina in the north and Kosovo in the south. A map showing the internal boundaries of Yugoslavia from this time would look familiar to the modern geography enthusiast, except for maybe Vojvodina (which is still an autonomous province of modern-day Serbia). These internal borderlines would become the international boundaries between independent states with the disintegration of Yugoslavia in the 1990s, though not without their problems. The SFRY started to fall apart after Tito’s death in the spring of 1980. The central government of Yugoslavia was never meant to be one of strength, with most of the power resting in the republics or even within the 500 communes from which they were made. President Tito was replaced by a rotation of regional leaders in an attempt to keep Yugoslavia together. It failed. Independence movements abounded in, and within, the various republics. And by 1990, the Yugoslav Wars were in full swing.

The modern day countries in the Balkans that once made up Yugoslavia

The Struggle Bus of Independence

Croatia and Slovenia were the first to declare independence, together, on 25 June 1991, although fighting continued there, especially between Croats and Serbs within Croatia for another four years.

Macedonia followed shortly after, declaring independence in September 1992. They were the only state to breakaway peacefully. Macedonia maintained good relations with Serbia and the rest of its neighbors.

But not so much for Bosnia and Herzegovina. Independence was attempted in 1992, but Bosnia and Herzegovina immediately went to war with itself. Bosniak Muslims and Croat Catholics fought against Serbian Orthodox Christians who had official and unofficial support from what remained of Yugoslavia and the SR of Serbia. The Bosnian Serbs took on the name of Republika Srpska after it lost direct help from Yugoslavia when Bosnia and Herzegovina gained UN recognition as an independent country. Peace was eventually brokered after a NATO bombing, and Republika Srpska rejoined Bosnia and Herzegovina as a federation.

(You are not alone in wrongly thinking that the two parts which make up Bosnia and Herzegovina were Bosnia and Herzegovina. Nope. Republika Srpska doesn’t get a name drop, but it is the second, largely autonomous, governing body in the federation. Here’s their government website for more information.)

Meanwhile, the SRs of Serbia and Montenegro remained united under the Federal Republic of Yugoslavia, eventually being renamed Serbia and Montenegro until Montenegro’s independence referendum in 2006.

In 2008, Kosovo declared independence from Serbia. Today, Kosovo’s independence is generally recognized, but it continues to be disputed by Serbia.

The Yugoslavia Legacy

In addition to war, Yugoslavia left behind a legacy of boundary disputes. All of the former Yugoslav states recognized that their borders as republics are now international frontiers, but what exactly does that mean forty years later? If a river (the Danube, for example) separated the SR of Croatia from the SR of Serbia but that river changed course since the 1950s (it has, a lot), what is the international boundary today? Is it the course of the river from the time of the internal Yugoslav lines (Croatia’s claim) or is it the modern course of the river (Serbia’s claim)? Croatia has these problems with every single one of their former Yugoslav neighbors.

North Macedonia is the only state born out of Yugoslavia to not dispute any of its borderlines. It recently resolved a conflict with Greece over its name by agreeing to the Republic of North Macedonia instead of the Former Yugoslav Republic of Macedonia. Bloomberg had a great article on this if you’re interested.

This long blog only addresses only a small portion of Balkan history. Volumes of books have been written on the subject, and I will likely be following this post with ones on modern territorial disputes of former Yugoslavia. I’m considering one on the evolution of the maritime boundaries in the region. I could also do a deep dive into why the Balkan Peninsula isn’t a peninsula, and why we really should be using Southeast Europe to replace the term “the Balkans.”

An Examination of Africa’s Maritime Boundaries

January 7, 2019
Marissa Wood

There are 57 States in Africa (with one count for Spain and their presence in the disputed Plazas de Soberanía, examined extensively here). 41 of these are coastal states, abutting the Mediterranean Sea, Atlantic Ocean, Indian Ocean, and the Red Sea. Of approximately 90 potential maritime boundaries, only 29 can be considered established.

Provisional Boundaries

To divide overlapping maritime space when there is no established boundary, provisional equidistance can be used to provide a picture of possible sovereignty outcomes should frontiers eventually be delimited. The count of 70 yet-to-be-established maritime boundaries is approximate due to the large number of disputed islands.

Madagascar, for example, is bordered by other Indian Ocean insular States including Comoros, the French island of Réunion, and Seychelles. In addition to these established entities are the disputed territories of Glorioso Islands (claimed by France and Madagascar), Mayotte (Comoros and France), Juan de Nova Island (France and Madagascar), Bassas da India (France and Madagascar), Europa Island (France and Madagascar), and Tromelin Island (France and Mauritius). Madagascar could have as many as 14 maritime boundaries with opposite States or as few as 7 depending on how the disputes are resolved. As it currently stands, Madagascar has only one established maritime boundary with the French island of Réunion which was agreed to in 2012 and follows an equidistance line.

Madagascar, disputed islands, maritime boundaries, and provisional equidistances lines.
Madagascar, disputed islands, maritime boundaries, and provisional equidistances lines.

Some other notable African maritime disputes include one between Kenya and Somalia, which is currently being adjudicated at the International Court of Justice (ICJ). There are also overlapping maritime claims between Morocco and Western Sahara (Morocco claims all of Western Sahara) and between Namibia and South Africa, who have an extremely small maritime dispute that is an offshoot of their unsettled land boundary in the Orange River.

If you want to know more about the provisional equidistance methodology, check out this post.

Established Boundaries

Colonial Maritime Boundaries

The oldest established African maritime boundary is from 1913 between modern-day Cameroon and Nigeria. In 1913, the colonial powers of Germany and the United Kingdom, respectively, established a land boundary separating their African territories. The territorial frontier ends in the thalweg of the Akpa Yafe River, and the colonial powers agreed to extend this out to sea. In 1971, independent Cameroon and Nigeria formalized the colonial border so that it continued from the land boundary terminus (LBT) in the mouth of the Akpa Yafe River for 11 nautical miles (M) (points 1 through 12) and then, in 1975, the two Parties again extended their maritime frontier for an additional 15 M (points 12 through G).

In the 1990s, relations between the two States became strained due to a vast territorial dispute that bled over into their maritime space. The conflict was submitted to the ICJ. The resulting 2002 Judgment resolved the dispute and further delimited their maritime boundary, leaving all but the tripoint with Equatorial Guinea fully delineated. In 2007, a Cameroon–Nigeria Mixed Commission transformed the turning points for the entire maritime boundary into WGS-84.

The maritime boundary between Cameroon and Nigeria.
The maritime boundary between Cameroon and Nigeria.

The runner-up for oldest established African maritime boundary is between Guinea-Bissau and Senegal, which was established by Portugal and France in 1960. Similar to the border between Cameroon and Nigeria, it was arbitrated by a special Tribunal in 1989 and then adjudicated by the ICJ in 1991.

Newly Established Maritime Boundaries

The most recently established African maritime boundary is between Côte d’Ivoire and Ghana, which was delimited in a 2017 Judgment by the International Tribunal on the Law of the Sea (ITLOS). Before the dispute began in the 2000s, the two Parties had generally adhered to a “customary equidistance line.” But after large hydrocarbon reserves were found just on the Ghanaian side of equidistance, Côte d’Ivoire began to claim a maritime boundary based on the bisector methodology. The Tribunal ruled in favor of an equidistance border because there were no special circumstances which required a deviation from a median line to produce an equitable result.

The second most recently established African maritime boundary is between Egypt and Saudi Arabia, agreed to in 2016, though Sudan disputes several points along the southern end of the line offshore from the disputed Hala’ib Triangle.

The maritime boundary between Egypt and Sauid Arabia.
The maritime boundary between Egypt and Sauid Arabia. Sudan disputes the boundary adjacent to Hala’ib Triangle.

Boundary Stats

The shortest African maritime boundary is between Seychelles and Tanzania at only 21 M, while the longest is between Italy and Tunisia at 590 M. The runner up for shortest is Cameroon–Nigeria at 40 M, and the second longest is Mauritius–Seychelles at 484 M.

As African States came into independence in the latter half of the 20th century, much progress was made in delimiting maritime space. There is, however, many boundaries still to be made and maritime disputes to be resolved.

US–Canada International Boundary: History, Disputes & More

October 30, 2018
Marissa Wood

The US–Canada border is the longest international land boundary in the world. Originally established by the 1783 Treaty of Paris and revised nearly a dozen times since, the International Boundary, as it is officially termed, comprises 5,450 total miles and touches eight provinces and 13 states. But scale alone doesn’t begin to describe this curious and sometimes confusing border.

Map showing the land boundary between Canada and the US
The US–Canada border has a rich, storied history.

More than 8,000 monuments and reference points and 1,000 survey control sites – maintained by the International Boundary Commission – dot the United States–Canada border. The boundary can be legally crossed via 119 official border crossing sites, six unstaffed road crossings, 13 international ferries and 39 rail crossings, as well as by air and sea.

United States–Canada Border History

The history of the US–Canada boundary is complex and long-reaching. Formally, it extends back to the very beginning of the United States as an independent nation.


Map of the United States of America Agreeable to the Peace of 1783 from the Library of Congress.

The first formal iteration of the International Boundary was established in 1783’s Definitive Treaty of Peace and Friendship between His Britannic Majesty and the United States of America, which ended the American Revolutionary War. The line between the new nation and Great Britain’s remaining North American colonies – which did not address territory west of the Great Lakes in detail – ran from “the North West Angle of Nova Scotia” to “the Northwesternmost Head of Connecticut River; Thence down along the Middle of that River to the forty fifth Degree of North Latitude.” The 45th Parallel was used as the dividing line west to the Iroquois River, and then roughly divided the Great Lakes.


The Jay Treaty created a boundary commission to better locate the boundary in the St. Croix River.


On 24 December 1814, the Treaty of Ghent formally ended the War of 1812. Among its provisions, the treaty restored the territorial status quo antebellum and called for the establishment of a demarcation commission to finalize issues related to the nascent boundary. The treaty is memorialized today by the Peace Arch, situated near the westernmost point of the US–Canada border in the contiguous United States.


The Treaty of 20 October 1818 – also known as the “Convention Respecting Fisheries, Boundary, and the Restoration of Slaves,” and the Convention of 1818 – addressed US fishing rights along the Newfoundland and Labrador coasts and provided for joint control of land in the “Oregon Country” for 10 years. Perhaps most critically, the treaty first set what would become a major piece of the US–Canada boundary along the 49th Parallel.


Did you know that Alaska was actually a part of Russia before it was purchased by the United States in 1867? The first international boundary established between Alaska and Canada was actually between Russia and the United Kingdom in 1825. This boundary delimitation would be accepted and confirmed by the US when it gained control of the territory in 1867.

Map showing the land boundary between Canada and Alaska
The Canada–United States (Alaska) land boundary has been fully demarcated even though it passes through some very cold, remote mountains.


The Webster-Ashburton Treaty of 9 Aug 1842, resolved the Aroostook War, a slight conflict sparked by significant disputes over the proper location of the international boundary between Maine and the British colony of New Brunswick. The 1842 Treaty also provided additional clarification on the boundary in the Great Lakes region and reaffirmed the 49th Parallel as the international boundary up to the Rocky Mountains.


The 49th Parallel was enshrined as the international boundary west of the Rockies by the Oregon Boundary Treaty of 1846. The agreement declared that “the line of boundary between the territories of the United States and those of her Britannic Majesty shall be continued westward along the said forty-ninth parallel of north latitude to the middle of the channel, which separates the continent from Vancouver’s Island, and thence southerly through the middle of the said channel, and of Fuca’s straits to the Pacific Ocean.” The Treaty, which also declared “free and open” navigation of the western waterways for ships of both nations, was the first to extend the US–Canada border from the Atlantic Ocean all the way to the Pacific Ocean.

For some interesting Canada–USA boundary oddities that were created by the Oregon Treaty check out this blog on Point Roberts!


The United States purchases Alaska from Russia for $7 million in a deal that is often called “Seward’s Folly,” after the US administrator who made the purchase. The old boundary between Russia and the UK is confirmed.


Following the Canadian Confederation of 1867, the 1873 Protocol on the Canal de Haro established a firm boundary in the Haro Strait between San Juan Island (US) and Vancouver Island (Canada).


In 1903, an international tribunal settled a dispute between the US and Canada over the boundary between Alaska and British Columbia in the Alaskan Panhandle. The two States would confirm the demarcation of the boundary following the Award in 1905.

For more about the boundary between Canada and Alaska check out our boundary page!


1908 saw two major milestones in the history of the border between the United States and Canada: the establishment of the International Boundary Commission and the US–UK Treaty of 1908, which called for new surveying between the St. Lawrence River and the Great Lakes, in addition to several minor boundary tweaks. A year later, the Boundary Waters Treaty of 1909 was adopted to prevent and resolve disputes over boundary waters, defined as the “main shore to main shore of the lakes and rivers and connecting waterways, or the portions thereof, along which the international boundary between the United States and the Dominion of Canada passes.”


In 1910, the Passamaquoddy Bay Treaty established an international boundary in Passamaquoddy Bay between Moose Island and Treat Island (US) and Campobello Island (Canada).


The 1925 “Treaty between Canada and the United States of America to Define More Accurately and to Complete the International Boundary between the Two Countries” finally codified large sections of the US–Canada boundary and formally established the International Boundary Commission.


The Atlantic Ocean maritime boundary between Canada and the United States has been and continues to be a contentious area. In 1984, after a series of failed negotiations, the International Court of Justice issued a Judgment in the Case Concerning Delimitation of the Maritime Boundary in the Gulf of Maine Area, which defined a partial maritime boundary between the two countries. Questions of sovereignty for Machias Seal Island were not addressed by the Court, and it remains in dispute (see below). 

The 1984 Canada–United States Atlantic Ocean maritime boundary, which has some remaining areas of dispute and contention.

Canada–United States Boundary Disputes

The United States, United Kingdom and Canada have engaged in numerous boundary disputes – largely peacefully resolved – since 1783. Four problem areas remain today.

Most notable among these is the controversy over Machias Seal Island. The sovereignty of the island, located about 10 miles off the coast of Maine in the Gulf of Maine’s “grey zone,” is disputed due to ambiguities in past treaties. The dispute is particularly heated given the area’s prolific lobster fishery, which has been open to Canadian lobstermen (by Canadian edict) since 2002. A Canadian lighthouse has continuously operated on the island since 1832.

Machias Seal Island has been disputed along the U.S.-Canada border for years.
Canada maintains a lighthouse on Machias Seal Island.

At the end of the land boundary in the Strait of Juan de Fuca, Canada and the United States have different interpretation of how the Pacific Ocean maritime boundary should continue westward. The two countries have differing equidistance claims, developed by utilizing different basepoints, resulting in slight differences between their sovereignty claims.

Parts of the Beaufort Sea, off the northern coast of Alaska and Yukon, are claimed by both nations as part of their exclusive economic zone (EEZ). The dispute exists in part because of differing interpretations related to the translations of the 1825 Anglo–Russian Convention.

Precise maritime boundaries around the Dixon Entrance between Alaska and British Columbia are in dispute as well. An “A-B Line” established in the 1903 Alaska Boundary Treaty is considered to be an international maritime boundary by Canada, but not the United States. The US, meanwhile, claims that equidistance is the correct arbiter of sovereignty in the area.

While not directly a matter of international boundaries, the countries differ in their interpretation of the waters of the Northwest Passage. Canada considers it “internal waters,” and therefore completely under the sovereignty of Canada, while the US regards it as an “international strait,” meaning that vessels of all nationalities should have free passage.

Status of the United States–Canada Border

The Canada–United States International Boundary is an undefended border, but it is illegal to cross the border outside of specified areas of control. Due to the good relations between Canada and the United States, there are large areas without fences or other controls. You can find information on crossing the US–Canada border here.

Numerous communities, a country club, a library and even several “line houses” are divided by the US–Canada border.

Check out some of our additional reports on the Canada–United States land boundary, the Alaska frontier, or the maritime boundary!

Newly Established Maritime Boundaries from Questionable Land Boundaries

July 27, 2018
Marissa Wood

What’s the deal with these new maritime boundaries from old, never fully defined or bilaterally agreed upon land boundaries? I’ve recently come across three of these scenarios, all, strangely enough, with former or current Dutch possessions.

In 2007, Guyana, a former British colony, had its maritime boundary with Suriname, a former colony of the Netherlands, awarded by the Permanent Court of Arbitration. In reading through court proceedings, their lack of an established land boundary felt like the elephant in the room. Much of their land border follows the western (Guyanese shoreline) bank of the Courantyne River, but at various points in history, the United Kingdom and later independent Guyana claimed the thalweg of the river rather than its shore. Today, it seems like the western bank is de facto accepted as the international boundary between them, though there is a large territorial dispute in the south over the New River Triangle. Despite the ill-defined land boundary, the Court was able to comfortably begin their maritime boundary on the low tide coast, and the maritime space between them is now well-defined and undisputed.

The map shows the 2007 maritime boundary extending from the de facto and disputed land boundary.

Saint Martin and Sint Maarten, which share an island in the Caribbean Sea, are both still connected to their colonial powers, France and the Netherlands, respectively. Sovereignty on the island was initially split in 1648, and not much additional definition to the land boundary seems to have been applied since. The eastern land boundary terminus (LBT) is in dispute as sovereignty over Oyster Pond is in question. And yet, in 2016, France and the Netherlands agreed to a maritime boundary dividing their Caribbean possessions. The eastern section of the maritime boundary begins at a point defined in WGS-84 on the coast, giving us a little more information about what must be the location of their land boundary. The western section, however, begins off the coast of Oyster Pond, allowing both countries space between their disputed land boundary and now established maritime boundary. This Agreement was ratified in 2017.

The map shows the undelimited land boundary and the 2017 established maritime border.

France also signed a boundary agreement with Suriname in 2017, marking the second current or former Dutch possession to have one of its maritime boundaries recently delimited. In this Agreement, they established a closing line across the mouth of the Maroni River where it empties into the Atlantic Ocean and began their maritime boundary from this point. Meanwhile, it is completely unclear as to the location of their land boundary in the Maroni River. France and the Netherlands made several draft attempts at formalizing the land boundary between their colonial possessions in South America, but due to a variety of reasons, including the disputes over the Maroni River and the source of the Kutari River and World War II, none of the agreements were ever signed.

The map shows the de facto and disputed land boundary along with the 2017 unratified maritime boundary.

There are a variety of factors which may contribute to the establishment of a maritime boundary beginning from a de facto or disputed land boundary. A primary motivation may be economic. There are an abundance of resources to exploit in the ocean—oil, natural gas, fish—all of which are more easily and efficiently obtained when the maritime boundary is well-defined.

Another factor may be a difference in perceived stakes/value. Territory on land is tangible: that tree over there, it’s definitely on the French side of Saint Martin. Maritime space, on the other hand, is vast and difficult to define. The average individual can only interact with maritime boundaries on maps and in media coverage. It is therefore easier for the public to allow for compromises to be made to delimit boundaries at sea than those on the ground.

In addition to the above reasons, land boundaries have centuries of baggage that go along with them. All of those agreements, drafts, meetings, and attempts at defining the boundary through here or there add up. Families for centuries may have thought they belonged to one country, but when a boundary is formally defined, end up in another. This causes all kinds of social issues. There aren’t people living in newly defined maritime space. Occasionally, historic fishing rights are impacted, but these are often addressed in negotiations or adjudication.

Or perhaps these successful maritime negotiations were the result of being a former or current colony of the Netherlands in the western hemisphere.

Korea and the Olympics

January 19, 2018
Marissa Wood

This is not a story about whose button is bigger but one of war, sports, and lines on maps.

The Korean Peninsula was first divided after World War II along the 38th parallel between a Soviet-protected north and a US-backed south. It was meant to be a temporary line of separation with the goal of restoring a unified Korean government after decades of Japanese occupation.

But by 1950 the icy fingers of the Cold War gripped the peninsula. The United States and the Soviet Union could not agree on a single Korean government. Then, on June 25, North Korean soldiers crossed the 38th parallel into South Korea, and the Korean War began.

Most of the fighting had trailed off by 1951 and talks of a truce had begun. However, an actual armistice agreement wasn’t signed until 1953. The line separating North and South Korea was adjusted from the 38th parallel to coincide with the frontlines at the end of the Korean War. A 2 km demilitarized zone extends on either side of the Military Demarcation Line.

While talks of reunification have occurred at various points throughout the 20th century, the 1953 Military Demarcation Line continues to serve as the de facto border between North and South Korea.

Soldier (D. E. Grenier) alongside a demarcation sign at Panmunjom, Korea in 1956. Uploaded to Wikimedia Commons by author Goldblatt.

The 2018 Winter Games in Pyeongchang are not South Korea’s first time hosting. Its capital city of Seoul held the 1988 Summer Olympics. North Korea refused to attend those Games and attempted to convince their communist allies to boycott the competition as well. The 1988 Summer Games are one of only two missed events since North Korea first started attending the Olympics in 1964. North Korean athletes have won a total of 55 medals excelling in summer sports such as weightlifting and wrestling.

South Korea has participated in every Olympic event since 1948 except for the 1980 Moscow Games. Their athletes have also performed well in the summer games, particularly in judo and archery, and have won over 260 summer and 50 winter medals.

Despite two years of icy relations between North and South Korea, a thaw set in after Kim Jong-un’s 2018 New Year’s Day address where the supreme leader discussed participation in the Pyeongchang Olympics. The two countries have now committed to walking under the Korean Unification Flag at the Opening Ceremony and creating a joint women’s ice hockey team. North Korea has plans to send a large group of athletes, a cheering squad, and other members of cultural demonstration groups across the 1953 Military Demarcation Line and on to Pyeongchang to compete in the 2018 Olympics.

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