The line that functions as a de facto boundary between Israel and Lebanon is not technically an international boundary but, rather, a line of withdrawal mandated by the United Nations in 2000 following the removal of Israeli military forces from southern Lebanon. The United Nations “Blue Line” was supposed to follow the boundary between Lebanon/Syria and Palestine as delimited by Britain and France in the early 1920s, but the demarcation is riddled with disputes and problem areas. The situation is further complicated by an abutting conflict between Israel and Syria over the Golan Heights, which was unilaterally annexed by Israel in 1981.

In 2022, Israel and Lebanon established their maritime boundary.