On Wednesday, Philippine soldiers found the beheaded bodies of two Vietnamese sailors who had been kidnapped eight months ago by the Abu Sayyaf group. The bodies were found on Basilan Island, about 240 kilometers from Marawi City where an ISIS-affiliated group has been fighting a battle with the Philippine Army for a month and a half.Basilan Island and its Sulu archipelago is part of the Muslim- majority Mindanao province of southern Philippines. It is only 320 kilometers from Indonesia and Malaysian provinces on Borneo.The ability of ISIS to put down roots through affiliates in Asia is of special importance as it loses ground in Mosul and Raqqa. What happens in the Philippines has ramifications for Islamist threats throughout the world.The 1995 Bojinka plot to blow up 11 airliners was masterminded by Ramzi Yousef and Khalid Sheikh Muhammad in Manila. Both men had a web of connections in Malaysia, Pakistan and the United States that connected them to the 1993 World Trade Center bombing and eventually to the 9/11 attacks. Abu Sayyaf’s murderous campaign against foreigners and other targets in the Philippines and Malaysia began in earnest in 2000 and it was once close to al-Qaida. In 2014 it began to draw closer to ISIS, which conquered vast areas in Syria and Iraq and declared a “caliphate.”In June 2016, Sidney Jones of the Institute for Policy Analysis of Conflicts in Jakarta told the NPR that Abu Sayyaf had been fractured into seven factions and retreated to Basilan. “Now we’re looking at where ISIS support is strongest is in the southern Philippines, it’s actually on Basilan, the site of the US triumphant victory in eradicating Sayyaf forces.”Isnilon Hapilon, an Abu Sayyaf leader emerged as a strong force in 2016. In battles with the Philippine Army, Moroccan and Indonesian fighters became the cadres of what was now an ISIS-affiliate.In January, according to a report at the website Rappler, Philippine Defense Secretary Delfin Lorenzana warned that ISIS had encouraged Hapilon to move to central Mindanao to create a wilayet or province of the caliphate using the Maute Islamist group there as a basis. “Central Mindanao is more conducive to the establishment of their wilayet,” Lorenzana said to reporters in January 2017. Pawel Wojcik, an analyst who tracks jihadist movements and has been following battles for Marawi for mPolska.pl, a Polish media outlet, says this year’s attack was long expected.“Insurgent attacks were increasing across Lanao del Sur and islands further south.”He says that Isnilon gathered numerous groups under a unified command and the attack on Marawi on May 23 shows how ISIS in the Philippines is being changed. “The worst is yet to come.”After ISIS established itself in Marawi the Philippine Army thought they could dislodge the extremists but have found themselves in a monthlong battle that continues to stretch on. Hundreds have been killed, including dozens of soldiers and civilians.Reports remind one of how ISIS operated in Mosul and Raqqa. A report at ABS-CBN News notes “bomb proof tunnels, anti-tank weapons hidden in mosques, human shields, mastery of the terrain.” As in Mosul, ISIS has burned churches, kidnapped priests and non-Muslim women and attacked a local college. In turn the government declared martial law across Mindanao.Local reports say there are around 500 ISIS fighters in the city, including 40 foreign fighters, which is also similar to the ISIS strategy in Iraq and Syria. Tens of thousands are displaced by the fighting. Even though Philippine President Rodrigo Duterte has vowed to “eat” the extremists, reports say he also favored a peace deal to end the crisis.Wojcik says East Asia jihadist forums see Marawi as a success and the longer the battle lasts, the more propaganda ISIS gets. He warns the new attacks may occur in South Cotabato and threaten the region.“China is well aware of this threat, hence a quick help that Chinese weapons companies delivered to the Filipino army.” China fears extremism in its western Xinjiang province while the US and Australia both have concerns about Islamist attacks across Asia. “The positive thing that has appeared during the Marawi siege is close cooperation between the Indonesian, Malaysian and Filipino navies,” says Wojcik. This has implications that stretch all the way to the Middle East. Foreign jihadists from the region have traveled to Asia to support ISIS there. In addition, these kinds of groups network, just as they did in the 1990s, with terrorist plans that affect India and countries throughout the world. Jerusalem, which just hosted the Indian Prime Minister and has security ties in Asia and the Philippines, should pay attention to Marawi.