Richard Heydarian is an Asia-based academic, columnist and author of "The Rise of Duterte: A Populist Revolt Against Elite Democracy" and the "The Indo-Pacific: Trump, China and the New Struggle for Global Mastery."
The Philippines has been host to two of the world's longest running insurgencies, Islamist and communist, which have ravaged its southern island of Mindanao since the 1960s. Over time, many rebel groups have radicalized and turned to acts of terror. The monthslong siege of Marawi by Islamic State-affiliated fighters in 2017 was a stark reminder of how profound the country's counterterrorism challenge is.