Chad–Libya border

Lines on a map

The line runs through barren, sparsely populated Sahara, over rock, pebbles and sand. Its eastern part goes back to an Anglo-French declaration of 1899 that limited the French zone by a line running southeast from where the Tropic of Cancer meets the 16th meridian; Italy accepted it in 1902, and a 1919 convention fixed its end at 19° 30′ N on the 24th meridian. The western stretch rests on no known treaty, apparently following the southern limits of Ottoman provinces on early maps.^[1]

A Franco-Italian agreement of 1935 would have moved the line well south, but it was never ratified. After Libya became independent in 1951, France and Libya signed a treaty in 1955 recognising the boundary as fixed by the earlier acts. Chad became independent in 1960.^[1]

The Aouzou Strip

From 1973 the two countries contested the Aouzou Strip. After restoring relations in 1988, they agreed in Algiers in 1989 to take the dispute to the International Court of Justice if talks failed.^[3] Libya argued that there was no existing boundary and claimed land on the basis of the rights of the local inhabitants, the Senussi order, the Ottoman Empire and Italy; Chad argued that the 1955 treaty had settled the line.^[2]

On 3 February 1994 the Court held that the 1955 treaty defined a complete and permanent frontier, which did not depend on the treaty remaining in force.^[2] Under an agreement of 4 April 1994, a mixed team of 25 Libyan and 25 Chadian officers oversaw the withdrawal of Libya’s administration and forces, and UN observers witnessed each handover.^[3]

“when a boundary has been the subject of agreement, its continued existence is not dependent upon the continuing life of the Treaty under which that boundary was agreed”^[2]