Philippine President Ferdinand Marcos later revived the claim and trained a number of Moro fighters to reclaim the territory in a secret mission named "Operation Merdeka". However, when the recruits gained knowledge of their true mission, most of them demanded to be returned home, as they did not want to kill their fellow Muslims in Sabah. Their request was denied; Marcos did not send back his soldiers but instead executed most of the fighters in an event known as the Jabidah massacre. This caused a southern Philippines insurgency to emerge, and the claim continued to be escalated by other claimants from the defunct Sultanate of Sulu. These claimants each attempted to give themselves legitimacy by self-proclaiming as the new Sultan of Sulu with support from politicians in the Philippine central government wishing to incorporate Sabah into the Philippines. Most new claimants and Philippine politicians today use the promised Malaysian lease payment as their main reason to take over the territory and also use it as a reason before the International Court of Justice (ICJ).