For years, most Asia analysts couldn’t imagine a more fearsome possibility than a nuclear North Korea. Presidents going back to George H.W. Bush have declared that Pyongyang must not be allowed to develop nuclear weapons—to no avail.

Yet as Pyongyang tested intercontinental ballistic missiles, President Donald Trump came along and threatened “fire and fury” if the Democratic Peoples’ Republic of Korea (DPRK) did not disarm. Presidential sidekick Senator Lindsey Graham dismissed fears of a U.S. attack on the North, opining that any war would be “over there” rather than “over here.”

But then Trump showed a willingness to talk, ending what had seemed like a slide toward war. After the Singapore meeting, he declared, “I want to bring our soldiers back home.” For years before being elected, Trump had railed against the South Koreans as well as the Europeans for underinvesting in their defense and unnecessarily relying upon America. He has since reiterated those criticisms as president.

These sentiments have horrified many of the same analysts demanding action to prevent a nuclear DPRK. Better, apparently, to remain in an entangling alliance that risks nuclear war than to end both the threat and the response taken to confront the threat. Better to leave U.S. cities vulnerable to annihilation than to return the burden of defense to an allied country grown wealthy under American protection. Members of the Korean policy community have decided that an even worse threat than nuclear war is the possibility of the president pulling troops out of South Korea and ending our alliance with Seoul. It is a case of extraordinary misplaced priorities.

The Korean saga began in 1945 with the defeat of Japan. The U.S. became involved on the peninsula when Moscow agreed to create two separate occupation zones, which became two competing nations. In 1950, the North’s Kim Il-sung invaded South Korea, starting the Korean War. U.S. and Chinese intervention followed, and the conflict did not end until 1953.

By then, the South had been ravaged by war, was politically unstable, and was headed by an aging and irascible authoritarian. Only continued American backing protected the ROK from falling to the well-armed North backed by China and the Soviet Union. An alliance appeared to be the only way to preserve an independent South.

That world disappeared long ago. Economic growth came to the South during the 1960s under the Park Chung-hee government. Democracy took longer, with the first free elections occurring in 1987. Today, South Korea has an economy 50 times the size of the North’s, along with twice the population, a vast technological edge, far greater international support, and a dominant industrial base. As for military power, the South’s is qualitatively superior. Only in raw numbers does North Korea lead.

Moreover, the Korean peninsula is no longer an important part of a larger global struggle involving America. The Soviet Union is gone, along with its alliance with Mao Tse-tung’s People’s Republic of China. Japan is strong and secure. There are no fears over American credibility and resulting implications for Europe’s defense. Washington certainly does not want war in East Asia, but a conflict between the two Koreas would look a bit like war between India and Pakistan: a potential humanitarian horror sure to unsettle economic markets and political systems in the region, but with no direct impact on U.S. security. The current confrontation is now someone else’s responsibility.

In short, the case for an American security guarantee and military presence has disappeared. Washington’s disengagement should not be precipitous, but it should have begun years ago, giving the ROK time to adjust its own security posture. If North Korea abandons its most powerful weapons and transforms its relationship with the South, the threat that has kept U.S. forces in the peninsula will have disappeared. They should then come home as a matter of course—quickly and without reservation.

Better then for Washington to offer to withdraw U.S. troops as part of a nuclear deal with the North. Their pullout could be phased in alongside North Korean compliance with the agreement. In this way, their departure, like their arrival, could be used to achieve a more lasting and stable peace.

Supporters of the alliance, who believe it is more important than ending the North Korean nuclear threat, typically point to other supposed benefits of America’s presence. The U.S. garrison is seen as having a dual use, containing China as well as North Korea. While Washington is not so impolitic as to admit as much publicly, those who see China as a potential enemy view South Korea as a vantage point from which to hem it in.

However, in practice, forces stationed in the South would be of little use against Beijing. A ground war against China would be madness. Thus the army division would be of little value: the South would be a base for a military build-up to nowhere. And no South Korean government is likely to join America in a war against China for any purpose other than to defend their own nation. After all, China has a long memory and will always be there.

Another claimed benefit is regional stability, though exactly what that means is usually left unexplained. Who, other than Pyongyang, would do what to whom if an army division was not stationed in South Korea? Where does one imagine those troops being deployed for action? Conflict in Southeast Asia or an implosion in Indonesia? These are not fights in which American forces belong. What else? Even in the unlikely event that South Korea allows American intervention, it would surely pale in comparison to the value of eliminating North Korea’s nuclear arsenal.

Finally, the U.S. presence is defended as a symbolic affirmation of Washington’s commitment to the region. But it’s still stupid to treat as unchangeable a commitment made nearly seven decades ago in a very different security environment and world. Even dependent allies would understand a change implemented to denuclearize the peninsula. Moreover, the primary signal of Washington’s commitment to Japan is the U.S. troops stationed there, not in the South. Forces in Okinawa are seen as backing the Korean commitment, not forces in South Korea as backing the Japanese commitment.

Of course, it is possible that the North would not seek an American withdrawal. Irrespective of its public pronouncements, Pyongyang might see the U.S. presence as a helpful constraint on Chinese influence after rapprochement with Washington, a bit like South Korea does. After all, in this case, the distant power is less likely to have direct territorial ambitions than the closer one. Or the DPRK might see no reason to pay for a withdrawal with concessions, since it might assume that a peaceful resolution of the Korean conflict will lead the financially hobbled United States to pull back on its own. However, possible rejection is no reason not to make the offer.

Most Washington policymakers appear to believe that “what has ever been must ever be” when it comes to foreign policy. Even after the Second Coming, they will argue that American forces must remain stationed in South Korea. The president obviously thinks differently.

Trump should put his skepticism of the value of permanent U.S. military deployments to good use. Offer a full withdrawal in exchange for denuclearization. It might turn out to be just the incentive necessary to turn North Korean promises into reality.

Doug Bandow is a senior fellow at the Cato Institute. A former special assistant to President Ronald Reagan, he is author of Tripwire: Korea and U.S. Foreign Policy in a Changed World and co-author of The Korean Conundrum: America’s Troubled Relations with North and South Korea.