Philippine relations with Malaysia have been bedeviled by a lingering dispute over the status of Sabah, the northeast corner of Borneo. The Philippines based its case on a claim to territories that were part of the former Sultanate of Sulu, a nineteenth-century entity whose territory straddled the present maritime boundary between Malaysia and the Philippines. In 1991 one descendent of the sultan, a Filipino citizen, still received a stipend stemming from cession of the sultanate to a British company. Philippine presidents have revived this claim occasionally. It was revealed in 1968 that Marcos was training a team of saboteurs on Corregidor for infiltration into Sabah. Marcos later decided to drop the claim, but the aggrieved Malaysians insisted on such an explicit, humiliating public renunciation that no Philippine president could meet their conditions. The Philippine constitution, by not mentioning Sabah, seems to have dropped the claim. Aquino rushed a bill to Congress in November 1987 to renounce the claim once and for all, hoping to get the issue out of the way before Malaysia's Prime Minister Mahathir bin Mohamad arrived for the ASEAN summit in December, but Congress did not act.

Data as of June 1991