
In Washington, the focus this week has been on the launch of a much-anticipated assault on Islamic State (IS) forces occupying the Iraqi city of Mosul.

In Southeast Asia, however, the Battle for Mosul is being greeted with ambivalence. Malaysia’s defense minister, Hishammuddin Hussein, said Monday that the country was worried and was monitoring the situation closely. On Tuesday, Singapore’s Home Affairs Minister K Shanmugam and Deputy Prime Minister Teo Chee Hean also expressed concerns about the impact that IS setbacks could have on Southeast Asia, speaking just after the city-state conducted its biggest ever counterterrorism drill. Both Malaysia and Singapore are the only two Southeast Asian members of the U.S.-led Global Coalition to Counter ISIL, with Indonesia thus far declining to join.

This ambivalence should come as no surprise. For Southeast Asia, the Battle for Mosul, and U.S. efforts against IS in the Middle East more generally, is a little bit of a mixed blessing. On the one hand, taking on the group where it is based and depriving it of territory is crucial to damaging its brand, which has been attractive to some Southeast Asians. Over 1,000 fighters have flocked from Southeast Asia to join IS in Iraq and Syria, and the group even has a Southeast Asia unit, Katibah Nusantara (Malay Archipelago Combat Unit), which now comprises around 700 fighters, largely from Indonesia, Malaysia and the Philippines but also a few from Singapore as well according to Malaysian defense officials.

But on the other hand, taking on IS at its base in the Middle East also increases the likelihood that other regions including Southeast Asia may become either a new home for IS recruits or an alternative target for attacks. We have already seen this dynamic playing out with a string of planned attacks by the group beyond the Middle East, including in Southeast Asia, with first attacks in Jakarta in January and Kuala Lumpur in June as well as a foiled attack on Marina Bay in Singapore. There have even been suggestions that the group could be looking at Southeast Asia as a place to establish a territorial foothold or base of operations.

But as IS gets squeezed out of the Middle East, the prospect of Southeast Asia becoming more of a target could also increase significantly. As the group loses territory, money, and manpower, members may return to their countries of origin in Southeast Asia and begin to collude with locals to either hatch new terror plots or engage in other criminal activities like kidnapping, smuggling or drug trafficking. The effects of this could either be immediate or more gradual. As Zulkifeli Mohammed Zin, chief of defense force of Malaysia’s Armed Forces, reminded those of us present at the Xiangshan Forum in Beijing last week, Jemaah Islamiyah, loosely referred to as the Southeast Asian offshoot of Al-Qaeda, was formed in the early 2000s with the help of returnees from the Afghanistan conflict.

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So even as we see IS lose ground in the Middle East, we can expect Southeast Asian countries to be on high alert and even intensify counterterrorism measures individually as well as collectively with other partners, focusing on areas like countering messaging, curbing financing, deradicalizing suspected extremists, and monitoring movements of potential recruits. At home, Malaysia has established a deradicalization center, Singapore is promoting greater interagency coordination and public awareness, while Indonesia is currently looking at toughening its laws.

These countries have also been leading discussions and conferences about terrorism among ASEAN countries and external partners, from the Counterterrorism Financing (CTF) Summit, co-hosted in August this year by Indonesia and Australia, to the U.S.-ASEAN Defense Ministers’ Informal Meeting, which took place in Hawaii a few weeks ago. In addition, Malaysia and Singapore have recently boosted their contribution to the U.S.-led Global Coalition to Counter ISIL, with Singapore announcing the deployment of a medical team to Iraq for around three months next year, and Malaysia agreeing to serve as the location for a regional counter-messaging center.

But it was clear from discussions with Southeast Asian officials present at the Xiangshan Forum – which had a session devoted to terrorism – that much more needs to be done and that they are prepared for things to get even worse as the campaign against IS intensifies in the Middle East, with hundreds of returnees as well as more links between IS and its various affiliates that operate in the subregion. To be sure, defense officials often think in terms of worse case scenarios and sometimes can exaggerate the true extent of threats, which can lead to consequences not just for counterterrorism responses, but other areas like rights and freedoms. But the tendency to overestimate threats is also an inherent part of ASEAN’s Islamic State conundrum, where Southeast Asian states think they should be even more prepared for short-term setbacks at home even as advances are made abroad that could pay off in the longer-term.