America’s Forever War Must Go On

Terrorists will continue mounting attacks. The United States cannot let down its guard.

A stylized GIF of a photograph of a crowd of soldiers
ERIC FEFERBERG / AFP / Getty; The Atlantic

About the author: Nicholas Grossman is an international-relations professor at the University of Illinois and the author of Drones and Terrorism.

Announcing the completion of America’s withdrawal from Afghanistan, President Joe Biden declared an end to the post-9/11 “forever war.” Ahead of the anniversary of the September 11 attacks that prompted the original invasion, Biden highlighted how, “if you’re 20 years old today, you’ve never known an America at peace.”

Despite the president’s spin, you still won’t. American forces have left Afghanistan, but soldiers, spies, and law-enforcement officials remain engaged around the world, and with good reason: Terrorists are fighting a forever war, which means the United States has to as well.

Biden’s case is based around the conclusion of the wars in Iraq and Afghanistan. The Iraq War technically ended in 2011, when the United States military withdrew. But America re-intervened in 2014 as the Islamic State captured Mosul and advanced on Baghdad. That deployment was much smaller than the six-figure occupation force of the 2000s, peaking at about 5,200 troops in 2017 and now down to 2,500. But the U.S. also sent troops into Syria, organizing local forces to fight ISIS, peaking at 2,000 soldiers and remaining at roughly 900. If Biden withdraws from Iraq and Syria, then the forever wars will finally be over, right?

Not quite. There’s also the drone program and Special Operations forces, which have launched hundreds of attacks against al-Qaeda’s offshoot in Yemen, al-Shabaab in Somalia, and other suspected terrorists, killing thousands of people. The most recent of these strikes outside of Afghanistan was barely a month ago, in Somalia. Few Americans pay attention to any of this.

There are also small U.S. military deployments throughout Africa, in at least 22 countries, partnering with local governments against groups connected, in some cases loosely, to the global networks of al-Qaeda and ISIS. Americans never pay attention to this either, unless U.S. soldiers are killed, as four were in October 2017 in Niger.

Let’s say America withdraws all these forces too. That decision would undermine military-to-military ties that help build international partnerships, but perhaps that’s an acceptable trade-off to end the forever wars. Intelligence and law-enforcement agencies—a big part of how the U.S. fights terrorism—will still operate overseas, though, and they have at times conducted abuses, and require active oversight.

The American people, not unreasonably, think terrorism is something the government should protect them from, like foreign invasion and serial killers. In a February 2021 Gallup poll, 72 percent of Americans said terrorism was a “critical threat,” a figure that has never dipped below 70 percent since Gallup began tracking the question in 2004. Similarly, polls show that a majority of Americans support drone strikes against foreign extremists. Biden authorized some against ISIS’s branch in Afghanistan following the deadly August 26 suicide bombing outside the Kabul airport, and promises to continue using these “over-the-horizon capabilities.”

This is the difficulty with claiming, or trying, to end the forever wars: Terrorism won’t go away. It’s an action, not an ideology. The international terrorist threat is a factor of globalization, American power, widespread access to guns and explosives, and the internet. There are and will be extremist ideologies, and they’ll always have the tools to organize. A subset of adherents will advocate anti-American violence, and some will attempt it. Terrorism will be a threat for the foreseeable future, and an ongoing warlike posture is necessary to counter it.

A lesson of September 11, embraced by politicians, the public, and the national-security bureaucracy, is that arresting terrorists after the fact isn’t enough. Nor is raising societal defenses, such as creating the Transportation Security Administration and heightening airport security checks. We have to anticipate and prevent attacks.

That requires intelligence to locate and track suspected terrorists, and capacity—whether that be law enforcement or military—to stop them. Doing it well means deepening relationships with foreign governments, sharing intelligence, and coordinating responses, which leads to outcomes like small deployments throughout Africa. When a state is either unwilling to oppose anti-American groups on its territory, as Afghanistan was with the Taliban government hosting al-Qaeda, or unable to, as in failed states such as Somalia and Yemen, that leaves American leaders with two choices: let suspected terrorists operate unimpeded, or send Americans to capture or kill them. American voters have made clear that the former is unacceptable. Drones and Special Operations forces seek to accomplish the latter.

But the Bush administration went further, expanding the War on Terror to states themselves. Defining America’s enemy not just as terrorists, but also “those who harbor them,” George W. Bush argued that by removing authoritarians, establishing elections, and training local militaries, the U.S. and its allies would deny terrorists sanctuary and reduce some of terrorism’s root causes.

This idea was straightforward with Afghanistan in 2001, where the Taliban rejected demands to hand over Osama bin Laden and expel al-Qaeda, but got stretched with Iraq in 2003, as Saddam Hussein’s government wasn’t involved with September 11, and did not have the feared weapons of mass destruction. But once U.S.-led invasions removed those governments, circumstances changed, and subsequent presidents committed to stabilization missions (albeit with an eye on the exit).

Bush’s vision of democratization by force was at best highly ambitious, and in some ways fundamentally misguided. The War on Terror, however, is neither misguided, nor has it been unsuccessful.

Presidents Barack Obama and Donald Trump continued and expanded operations against al-Qaeda, and later ISIS. Both ordered ground raids that killed the leaders of jihadist organizations. Drone-strike data show remarkable continuity between those otherwise different administrations.

Although some people probably do join terrorist groups because someone they care about was killed or injured by an American drone strike, these attacks likely do not create more terrorists than they kill—or at least not terrorists of equal ability. As research by Patrick Johnston and Anoop Sarbahi, Asfandyar Mir, and other academics shows, the drone campaign has reduced the effectiveness of targeted groups by removing skilled leaders and frightening operatives into curtailing communication and recruitment. When strikes kill civilians, it’s tragic (and strategically counterproductive), but drones tend to cause fewer civilian casualties than other military options, and improved abilities led to fewer civilian deaths per strike in the 2010s than in the 2000s.

Congress has authorized drone strikes and other War on Terror operations in all sorts of ways, to the point where they’re a permanent part of the federal bureaucracy. There’s the 2001 Authorization for the Use of Military Force against terrorists, which grants the president broad power to designate threats and determine appropriate responses. Congress passed it near-unanimously, with just one House Representative, the Democrat Barbara Lee of California, voting no. Every president since has interpreted the authorization expansively, using it to go after not only al-Qaeda, but also suspected terrorists who had no role in September 11.

Even if Congress repealed the AUMF, it still authorized extensive surveillance measures in the name of fighting terrorism via the Patriot Act of 2001, and reauthorized much of it in 2015 and again in 2020. Acts of Congress created the Department of Homeland Security in 2002, and restructured the intelligence community in 2004. And Congress effectively reauthorizes their activities every year by approving budgets.

The War on Terror is like the War on Drugs: an ongoing issue to manage, not a conflict that can be won. The U.S. has made mistakes, done some awful things—such as a torture program in the 2000s—and can improve its strategy in various ways. Washington should, for example, learn the lessons of the past 20 years, namely that the U.S. should avoid upending relatively stable situations, such as Hussein’s Iraq, while also recognizing that the costs of ignoring problems, such as 1990s Afghanistan, can end up higher than the costs of managing them.

Ending America’s deployment in Afghanistan is a significant change. But terrorism, whether from jihadists, white nationalists, or other sources, is part of life for the indefinite future, and some sort of government response is as well. The forever war goes on forever. The question isn’t whether we should carry it out—it’s how.