Escalating ISIS threat in Southeast Asia: Is the Philippines a weak link?

Singapore (CNN) Since videos of Southeast Asian recruits fighting under the black flag of ISIS emerged two years ago, the appeal of the terror group has been gradually growing in the region. Several militant groups in Indonesia have already sworn fealty to ISIS, as did those behind the Jakarta bombing, while in Malaysia, "lone wolf" ISIS sympathizers have been active on social media. Several hundred Southeast Asians are now in Syria and Iraq, where they have formed Katibah Nusantara, which claims to represent Southeast Asians fighting for the ISIS cause. An upsurge in ISIS-related activity in the southern Philippines has heightened concerns that the region could soon become a de facto "wilayat," or province of the "Islamic State."