We Still Haven’t Figured Out How to Beat ISIS

For all of the counterterrorism wins that the United States has had in its fight against the Islamic State — and there have been many — we still have not figured out how to defeat it.

A terrorist attack targeting a concert hall in the Russian capital of Moscow on March 22 killed more than 130 people and left many others severely wounded. It served as the latest deadly reminder that the Islamic State — and particularly its Khorasan branch, ISIS-K, which is active in Afghanistan, Iran and Pakistan — remains a potent threat. It’s a painful lesson Afghans and Americans alike learned in August 2021, when ISIS-K conducted a complex suicide operation that killed at least 170 Afghan civilians and 13 American service members in Kabul, in the midst of a chaotic U.S. withdrawal from Afghanistan.

Since the start of the new year, ISIS-K has launched lethal assaults in Iran and Turkey. Several ISIS-K plots in Europe have been disrupted, with arrests in Austria, France, Germany and the Netherlands. On Tuesday, four days after the Moscow attack, the ISIS-affiliated al-Battar Media published a message threatening Italy, France, Spain and Britain: “Who’s next?” Both France and Italy have since raised their terror threat levels.

All of these events point to what we now know: Stripping the Islamic State of its self-proclaimed caliphate is not the same as beating it. At its peak, the caliphate was as large as the territory of Britain, stretching from the Levant to Southeast Asia, and boasted over 40,000 foreign fighters from more than 80 countries. Forced from this redoubt, ISIS has reconstituted itself in other countries, going underground in less detectable — but more dangerous — forms.

To stop that threat from reaching America and its allies, the United States must prevent two decades of counterterrorism expertise from atrophying. There are other serious threats that deserve Washington’s attention, including Chinese adventurism and the challenge of artificial intelligence. But to keep Americans safe, counterterrorism must remain a strategic priority — and that includes finding a way to keep eyes on the Islamic State in parts of the world where we no longer have a footprint.

After the terrorist attacks by Al Qaeda of Sept. 11, 2001, the American public was told to brace itself, that the war on terror would be a generational one. The United States made some profound blunders in the decades-long fight that followed, and eventually, Washington turned its national security focus to different geopolitical threats. But neither of those facts obviated the need to remain committed to countering transnational terrorism. By pulling back troops and intelligence assets from active conflict zones, the United States has allowed groups like ISIS-K to rebound. It’s not the time to let up, or predictably, we will find ourselves facing a resurgent adversary.