Resolving the militarised border dispute between Guinea-Bissau and Senegal


French Diplomacy helped to prevent border clashes from escalating while the arbitration of the ICJ resolved the territorial dispute between the two countries.

In 1974, the government of newly independent Guinea-Bissau sought to confirm their international borders to facilitate trade and economic development. Like in most African states, these were inherited from the former colonial power – in this case, Portugal. A point of contention emerged with neighbouring Senegal concerning potentially rich offshore resources. This was compounded by alleged Bissau-Guinean support for armed opposition groups in the Senegalese region of Casamance, which is located directly across the border. Bilateral negotiations over the border began in 1977 but were ultimately fruitless, leading the Senegalese and Bissau-Guinean governments to refer the case to an independent arbitration tribunal in 1985.1 When the findings of the tribunal were rejected by the Government of Guinea-Bissau in 1989, the case was referred to the ICJ. In April 1990, while the case was being assessed in The Hague, Senegalese troops and military aircraft were spotted operating in Bissau-Guinean territory. The following month, Bissau-Guinean forces clashed with Senegalese troops, leaving 17 soldiers dead.2 With the dispute becoming increasingly militarised and armed forces lining up against each other along the border, the prospect of an interstate conflict was significant.

Fearing that the crisis could rapidly escalate into a major war, the Government of France invited ministers from both states to Paris for emergency talks on 23 May 1990.3 This meeting served to immediately defuse tensions, and the following day Guinea-Bissau and Senegal withdrew their armed forces from their mutual border to minimise the risk of future clashes. On 12 November 1991, the ICJ issued its judgement on the dispute, dismissing Guinea-Bissau’s appeal and affirming Senegal’s sovereignty over the disputed maritime territory. This time, the findings were accepted by both parties. Since the settlement, bilateral ties have improved and the states now cooperate in several fields, including the development of maritime resources. While the land border remains a cause of tension given relatively frequent incursions by Senegalese forces pursuing militants from Casamance (including in 2000 and 2009), improved ties between the two governments and the mechanisms established to resolve the maritime boundary dispute (such as a joint border commission) have prevented any major escalation.4

1 Ifesinachi Okafor-Yarwood. “The Guinea-Bissau – Senegal maritime boundary dispute” Marine Policy, Vol. 61, No. 1. (2015) p.286

2 AP News. “Senegal, Guinea Bissau Agree to Pull Back Troops in Dispute.” AP News. (24 May 1990) Available at: (Accessed 25/10/2021)

3 UK Parliament. “Senegal/Guinea Bissau Dispute.” Hansard: House of Lords, Vol. 520. (1990) Available at: (Accessed 25/10/2021)

4 Reuters Staff. “Senegal, Bissau deny border dispute.” Reuters. (24 October 2009) Available at: (Accessed 25/10/2021)

Start Year


End Year




UN Regional Group


Type of Conflict

Risk of an interstate conflict

Type of Initiative

Diplomacy, Resolution of a militarised territorial dispute

Main Implementing Organisation(s)

The Government of France and the International Court of Justice (ICJ)




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