As negotiations heat up with the Afghan Taliban, the United States needs a new strategy for Afghanistan, one that meets America’s core security interests and is sustainable for many years to come. For nearly two decades — and across three successive US presidential administrations — US policy has been paralyzed by endless debate between two repellant options.

The first, staying the course and keeping US troops in Afghanistan until the country becomes a stable democracy, has long since proved a failure. We have sacrificed thousands of American lives, more than 100,000 Afghan lives, and hundreds of billions of dollars, and still we have achieved nothing. Indeed, America’s grand strategy is not simply failing to create a stable democracy — it is galvanizing vast portions of the country against America. The US Special Inspector for Afghanistan Reconstruction recently estimated that 60 percent of Afghan territory is under the control or significant influence of the Afghan Taliban, including non-Pashtun populations that resisted the group in the past.

The second option is simply to declare victory and go home. In that scenario, we implicitly accept failure and walk away. But this would entail the all-too-real risk that another international terrorist group bent on attacking America or its Western allies will use Afghanistan as a base to plan, organize, and execute future attacks. Indeed, US intelligence cautions that a future attack could occur in as little as two years if America simply walks away.

Fortunately, there is a third option: Off-shore balancing. This approach would remove US combat troops from Afghanistan in the near term, while balancing against threats from international terrorist groups by establishing long-term partners inside Afghanistan and relying on regional bases in neighboring countries.

With off-shore balancing, America’s aim is to work with the Afghan government and local groups as partners. The role of US forces would be limited to providing political, intelligence, and economic support. Accordingly, regional bases would not house heavy combat forces, but instead would offer surveillance and intelligence gathering as well as political and economic assistance to partners within the country. These regional bases could also serve as launchpads for future re-deployments of air, naval and even ground forces, if necessary.

Off-shore balancing is sensible because it can achieve our most important national security objective: to prevent international terrorists from gaining political and military control of any of the 400 districts in Afghanistan. Operationally, the objective should be to prevent an international terrorist group from gaining territorial control of any district in Afghanistan — that is, political control of a district capital and sufficient military control of areas within a district for training camps for, say, 50 to 100 international terrorists to prepare, plan, organize, and execute attacks effectively unimpeded by counter-pressure. The strategy is feasible because the United States has already established a number of bases in neighboring Turkmenistan, Uzbekistan, and Tajikistan. In addition, the United States and its allies also have powerful surveillance capabilities and the wherewithal to provide targeted support to in-country political partners.

But the strategy comes with a caveat. The United States must be willing to work with the Afghan Taliban. Many people will find such an alliance distasteful, especially since it was the Afghan Taliban that harbored Osama bin Laden and Al Qaeda in the 1990s. But is important to recognize that the Afghan Taliban is not an international terrorist group. While violently repressive and hardly liberal, it has never carried out or sought to inspire a campaign of terrorism in the West.

Indeed, its strong interest has long been to protect its status as the top governing organization in Afghanistan. The group’s appeal last February for the United States to start peace talks shows it is against the US occupation — not against US values as an existential threat that must be destroyed.

For three years, there has been a compelling reason to think that the Afghan Taliban has its own political motives for resisting and combating international terrorist groups.

That reason is the Islamic State — which in 2015 began to infiltrate Afghanistan.

The two groups are bitter enemies and they attack each other at every opportunity. Last summer, the Islamic State had a major presence in the northern district of Darzab. Following a two-day battle last August, however, the Afghan Taliban decisively defeated the Islamic State in Darzab, with more than 200 Islamic State fighters surrendering to the Afghan government to prevent capture by the Taliban.

Their ongoing conflict explains why the Afghan Taliban has tacitly cooperated with the United States. In June, for example, the Taliban agreed and remained faithful to a negotiated cease-fire during major Islamic holidays, an agreement that allowed the United States and Afghan government forces to concentrate on a major air and ground offensive that successfully routed the Islamic State from multiple districts in its eastern stronghold, Nangarhar Province.

Thus, the Afghan Taliban is demonstrating by deeds, not merely words, that it wants to rid Afghanistan of international terrorist groups, not harbor them. In effect, the Afghan Taliban is now aligned with the highest security priority of the United States and its allies.

To be sure, America should not simply trust that the Afghan Taliban will always oppose a sanctuary for international terrorist groups. However, the alignment of interests and tacit cooperation between the United States and the Afghan Taliban creates an excellent basis for the transition to off-shore balancing.

Off-shore balancing is not perfect. It cannot guarantee a stable democracy or prevent all violence in Afghanistan. Nor can it guarantee that the United States and the Afghan Taliban will sign a formal political settlement, or that individual or tiny clusters of terrorists will not hide out in the country. However, all of these broader goals are more likely if America adopts off-shore balancing, a strategy based on core national security interests that can be sustained for decades.

Off-shore balancing has a track record of success. America relied on this strategy to topple the Taliban and kick Al Qaeda out of Afghanistan after 9/11, and we relied on it again to eliminate the Islamic State’s operational sanctuaries in Iraq and Syria from August 2014 to 2018. In both cases, the US delayed before adopting this strategy until after international terrorists controlled major areas. We should not delay in Afghanistan.

We have arrived at an extraordinary moment, when the interests of the Afghan Taliban are aligned with the highest security priority of the United States and its allies. We must seize this opportunity and leverage it for our own best interests and for the future of Afghanistan.

Robert A. Pape is professor of political science and director of the Chicago Project on Security and Threats at the University of Chicago.