Burkina Faso–Niger Frontier Dispute case

The section in dispute between the Tong-Tong astronomic marker to the Botou bend was further divided into four sections:[13]

1. From the Tong-Tong astronomic marker to the Tao astronomic marker;
2. From the Tao marker to the River Sirba at Bossé-bangou;
3. From Bossé-bangou to the intersection of the Sirba with the Say parallel;
4. From the intersection to the point located 1200m to the west of the village of Tchenguiliba, referred to as the Botou bend.

Source:[14]

Both Parties were in agreement on the location of the Tong-Tong astronomic marker at 14° 25´ 04˝N, 00° 12´ 47˝E, but had slightly different coordinates for the Tao marker. The court found it unnecessary to determine the precise location of the Tao marker as it was not a point of significant disagreement, and the Parties could determine the co-ordinates during demarcation operations.

The 1927 Arrêté had not specified how these two points should be connected, so the Parties differed in how it should be interpreted. Burkina Faso argued that the failure to specify implies these points should be connected with a straight line. Niger relied on a Record of Agreement of 13 April 1935 that had been established to settle a dispute between the residents of Dori and Téra. It referred to the 1927 Arrêté and asserted a notional line between the two markers, but running through a marker at Vibourié, situated east of a straight line between the markers.

A map of the Burkina Faso-Niger border at 18 November 1974, by the US State Department.

The court held in favour of Burkina Faso. It believed that the easterly location of the Vibourié marker was a topographical error, as the Record of Agreement made clear the drafter believed the marker to lie on the straight line between the Tong-Tong and Tao markers.

Source:[15]

The 1927 Arrêté was again imprecise on how these points were to be connected. Burkina Faso took the same reasoning as for the first section, that the implication should be a straight line. Niger argued that as the 1927 Arrêté was imprecise, reference should be to the 1960 map as the Parties had agreed to in article 2 of the special agreement.[6] The border on the map was sinuous, however Niger further departed from it in their drawing to the effect that the border would run to a point north-west of Bossé-bangou. They relied on the descriptions of the area from other documents that suggested the 1927 Arrêté was incorrectly drawn on this point. The 1927 Arrêté's raison d’être was to delineate new borders after the transfer of certain districts from the Colony of Upper Volta to the Colony of Niger, and the border it delineated did not properly account for those districts. Niger argued that according to the principle of uti possidetis juris, in the absence of legal title the border should be drawn according to the effectivités.

The court held that its mandate was to interpret and apply the 1927 Arrêté and, if it were inadequate, to use the 1960 map and not other principles of law. The court decided to follow the line drawn on the 1960 map; not in reasoning, but in effect a middle-ground between the Parties.

The court considered that as villages on either side of the border required access to water, the 1927 Arrêté would have intended the border to on the median line of the River Sirba and not on either bank. It found the wording was then clear on the border following the Sirba upstream and departing and turning at intersections of the river with lines of longitude and latitude, the final turn at the longitude where the Say parallel intersects with the River Sirba (at 13º 06’ 12.08”N, 00° 59´ 30.9˝E).[16]

Both parties agreed on the point referred to as the Botou bend. Having located the intersection, the court had only to determine the line between these two points. Burkina Faso argued the 1927 Arrêté specified that this would be a straight line. Niger relied on colonial and postcolonial effectivités to argue that the two nations had come to an implicit agreement regarding a line that closer followed the 1960 map. Burkina Faso disputed this and the court found it had no evidence of such an agreement, concluding that the 1927 Arrêté was clear and should be followed.[17]