It’s not clear how much the killing of al-Qaeda leader Ayman al-Zawahiri in Kabul, announced by President Joe Biden on Monday night, will affect the terrorist group’s ability to function. But in symbolic terms, Zawahiri’s death at the hands of an American drone is undoubtedly significant: It sounds the final note of the war on terror era in US foreign policy.

Though Zawahiri’s role in the 9/11 attack is often overstated, he was the last high-profile al-Qaeda figure involved that remained at large. Before he was Al-Qaeda’s chief, he was the group’s top ideologist — helping develop its pioneering strategy of targeting the “far enemy,” meaning the United States, as part of a broader campaign to overthrow US-aligned governments in the Middle East. Over the last three administrations, the US has invested massive resources in countering this strategy, including a decade-long hunt for Osama bin Laden culminating in a 2011 raid on his compound in Pakistan.

Zawahiri’s death another decade later concludes the long quest for revenge for the Twin Towers. While US global counter-terrorism operations will continue, the belief that terrorism is the priority for US foreign policy has largely departed official Washington. In fact, it has been gone for quite some time.

During the Obama and Trump presidencies, the US foreign policy community became more and more concerned with “great power competition” — meaning challenges posed by Russia and China — and less interested in centering terrorism. Biden’s two most notable foreign policy initiatives, the withdrawal from Afghanistan one year ago and the aggressive response to Russia’s invasion of Ukraine, solidified the American reorientation. By Tuesday morning, Zawahiri’s death was no longer the top story on the New York Times homepage; it had been replaced by tensions with China surrounding House Speaker Nancy Pelosi’s visit to Taiwan.

By the time of his death, Ayman al-Zawahiri led a less threatening al-Qaeda that no longer occupied the central place in global affairs that it once took. He lived just long enough to see the world pass him by.

America has finally moved on from 9/11

In the commentary surrounding the strike on Zawahiri, experts have noted one point again and again: The attack was executed after the US ground withdrawal from Afghanistan. The force of the observation is that the United States managed to find and kill one of its top terrorist targets without major military resources on the ground or a local partner government that could routinely help it identify potential targets for drone strikes and special forces raids.

This suggests one of the major arguments against the Afghanistan withdrawal — that the US needed a presence on the ground to fight al-Qaeda — was at least partially wrong. It also suggests that, going forward, the United States will continue to engage in intermittent strikes on what it sees as particularly dangerous terrorist targets abroad. The end of Zawahiri does not mark the end of sustained, low-level US military operations in places like Afghanistan and Somalia.

But the continuance of counter-terror operations is not the same thing as a full-fledged “war on terror.” In President George W. Bush’s administration, terrorism became an all-consuming preoccupation — the sun around which all other foreign policy thinking revolved. Jihadism was seen as the central ideological challenge of our time; the war on terror was commonly described as a decades-long struggle akin to the Cold War struggle with the Soviet Union.

As time went on, however, it became clear that terrorist groups were not nearly so threatening.

While the big invasions of Iraq and Afghanistan turned into quagmires, the international coalition against ISIS launched in 2014 proved that more limited military operations could do major damage to jihadist groups in their strongholds. At home, Western counter-terrorism capabilities have become exceptionally strong, with intelligence gathering and surveillance operations so powerful that executing 9/11-style attacks has become prohibitively difficult.

“Spectacular though the 9/11 attacks were, they did not, as many feared, indicate that large and powerful terrorist organizations had laid down roots in the West and threatened the foundations of its social order,” leading terrorism analyst Thomas Hegghammer writes in Foreign Affairs. “In retrospect, [Osama bin Laden’s death in] 2011 did mark the end of al Qaeda’s war on the West. The group lives on as a set of regional militias with local agendas in places such as Somalia, but it has not successfully conducted a serious attack on the West for almost a decade.”

This does not mean al-Qaeda is finished as an organization. A recent UN report concluded that the group may plausibly retake ISIS as the leader of the global jihadist movement, something analysts have warned about for years.

Rather, it’s that both al-Qaeda and ISIS are less capable of conducting and inspiring transnational attacks than they were at their respective peaks (2001 and 2014). This makes them less of a priority for Western policymakers at the same time as a more traditional threat — strategic competition with other nation-states like Russia and China — became a bigger concern.

In 2018, then-Defense Secretary James Mattis announced that “great power competition —not terrorism — is now the primary focus of US national security.” In 2021, Biden described the struggle between democracy and autocratic powers, not terrorists, as “the central challenge of the age.”

The war on terror, as a paradigm, was a clear failure. It led the United States to engage in disastrous long wars, kill tens of thousands of innocent civilians, and downplay bigger strategic challenges (like China) for too many years. Yet for all those disasters, certain specific policies — including more limited military interventions and increased funding for intelligence operations targeting terrorist groups — did succeed at significantly diminishing the threat to the American homeland.

Zawahiri’s death may or may not weaken al-Qaeda; the historical track record on killing terrorist leaders is decidedly mixed. But in a deeper sense, the kind of threat he once stood for is (mostly) already gone.