In a follow-up to the joint maritime patrol in the Sulu Sea last June, Malaysia, Indonesia and the Philippines launched another joint patrol on Thursday to monitor and respond to suspicious activity in the Sulu Sea – waters known to be plied by suspected terrorists. Malaysian Defense Minister Hishammuddin Hussein said the tri-nation effort was necessary given the “activation of this maritime domain by terrorist organizations as a base for operations”. The Philippines, in particular, has seen the rise of militancy in the region with the months-long siege of Marawi City by the Islamic State-inspired Maute militant group.