A botched raid on a guerrilla stronghold in the city of Marawi has exposed the growing strength of Muslim extremists in the Philippines. The city of 200,000 has become a battle zone, with much of the population having fled. President Rodrigo Duterte has declared martial law in the southern Philippines and has threatened to extend it to the entire country. Given his record, that step must be avoided. But the battle for Marawi has important lessons for the Philippines and Southeast Asia.

The government of the Philippine has long battled separatist forces in the predominately Muslim province of Mindanao. Manila has largely prevailed, splitting the rebel groups and striking peace agreements with some, while continuing to fight the holdouts. In many cases, the remaining militants are more properly considered criminal gangs that engage in kidnapping and extortion rather than real separatists. They are vicious and deadly, nonetheless.

The most recent spasm of violence erupted last week when government forces attempted to capture Isnilon Hapilon, an Islamic preacher and former leader of the Abu Sayyaf Group (ASG), one of the remaining criminal gangs. Since leaving ASG, Hapilon has pledged his allegiance to the Islamic State group, and united a number of smaller extremist groups, including the Maute, an especially well-armed group with a presence in Marawi, to fight under the black IS flag. Hapilon's work has earned him a spot on the "10 most wanted terrorists list" of the U.S. Federal Bureau of Investigation and a $5 million bounty.