It's tempting to see the Islamic State's retreat in Iraq and Syria as an American victory, but at a House Homeland Security Committee hearing last week, several terrorism experts issued a stark warning: don't gloat; stay the course.
Though badly damaged territorially, Islamic State has not been defeated, they maintained. They warned that it would be a major strategic blunder to declare victory prematurely and withdraw American forces from the fight. They agreed that ISIS is much diminished but observed that its "virtual caliphate" remains capable of carrying out lethal attacks and inspiring mayhem at home and abroad—and that the movement underlying it, militant Islamism, continues to grow.
President Trump has often pledged to bring most U.S. forces home to "rebuild America." That desire potentially affects not only the 2,000 troops now stationed in Syria but also the roughly 30,000 deployed in South Korea since the end of the Korean War 65 years ago. The Washington Post reported in March that Trump had threatened to withdraw those troops if he did not get his way on trade. White House chief of staff and retired Marine Corps general John Kelly managed to talk him out of it.
The ISIS threat may have receded in the American consciousness, but the Islamist militant threat has metastasized and may even be quietly escalating, the experts warned. Committee chairman Michael McCaul, a Texas Republican, noted that al-Qaida still has tens of thousands of fighters scattered around the globe. Withdrawing U.S. forces would cripple the progress made against Islamist extremism and give militants the breathing room required to recover, regroup, and rebuild, McCaul said. "The leadership is still there," agreed retired Army general Jack Keane, a key promoter of the "surge" in Iraq who informally advises Trump's military team. Militant fighters who remain in "pockets on the ground" in Iraq and Syria and "hiding in the shadows" in Europe will try to reconstitute, he said.
In Libya, despite losing its base in Derna and Sirte, ISIS maintains a force of 4,000 to 6,000 fighters. In Africa's Sahel, ISIS forces roaming the region killed four U.S. soldiers and five Nigerian soldiers in October 2017 in an ambush of a joint U.S./Nigerian patrol near the Mali-Niger border. After Boko Haram, Africa's deadliest terror group, pledged allegiance to ISIS in March 2015, it divided into two factions, both of which continue to kidnap and kill African soldiers, officials, and civilians, despite a multinational joint counterterror task force of 8,700 troops. Since its formation in Egypt's Sinai Peninsula in 2011, ISIS has killed dozens of Egyptian military and security forces, bombed Coptic churches in Alexandria and Tanta, and carried out lethal bombings and attacks in Cairo. Despite counterterrorism assistance from Washington and (more quietly) Israel, Egyptian forces have been unable to dislodge the deeply embedded group. ISIS has conducted deadly attacks against civilian and military targets in Kabul from its foothold in Afghanistan, which Keane warns could expand into a "bona fide safe haven." In the Philippines, it took security forces five months and more than 1,000 deaths to defeat pro-ISIS militias that had overrun Marawi, in the southern island of Mindanao. ISIS is planning to regroup there and in its original bases in Iraq and Syria.
Daveed Gartenstein-Ross, an analyst with the Washington-based Foundation for the Defense of Democracies, warned that while ISIS has lost territory, money, and stature since 75 nations joined the U.S.-led coalition to defeat it and other like-minded groups, militant Islamism as a movement has continued to thrive. "The global jihadist movement's overall trajectory is one of growth, not of decline," he said. Joshua A. Geltzer, who served as President Obama's senior counterterrorism director on the National Security Council, cautioned that the "last mile of defeating a terrorist group can be the hardest," as the United States "learned all too well from the lingering remnants of ISIS's predecessor, al-Qaeda in Iraq."
The experts also believe that sustaining focus on the counterterrorism mission in light of the Trump administration's successes against ISIS will be challenging, especially because military victories tend to mask the depth and complexity of the Islamists' appeal. At its peak, ISIS governed 7.7 million people and controlled roughly 40,000 square miles of land, what Keane called a "proto-state" as large as Britain. Through illegal sales of oil and antiques, the extortion and taxation of local populations, and kidnappings for ransom, ISIS earned roughly $80 million a month by the end of 2015 and fielded an army of 40,000 to 60,000 fighters, from more than 100 countries. Since coalition military operations belatedly got underway in Iraq and Syria, ISIS has lost 90 percent of the territory it once controlled, including Mosul and its former capital, Raqqa. But an estimated 3,000 to 5,000 fighters remain in the area, and the group still earns an estimated $4 million per month from oil sales and black market antiquities trading. Fueled by bad government, the spread of ungoverned spaces, and economic and political frustration, the Islamists' appeal remains powerful, all concurred.
"Only if we walk away can such groups regroup," Keane declared, arguing that Obama's withdrawal from Iraq in 2011 and his reluctance to get involved in the Syrian civil war had enabled ISIS to take root there. This time, he told the skeptical congressional panel, "we must finish what we started." Going home now both "physically and psychologically" would be a "serious strategic blunder," he said. But given the nation's distaste for foreign adventuring and its exhaustion after 16 years of war, it is a blunder that the U.S. might well make.