The summit between President Donald Trump and North Korea’s Supreme Leader Kim Jong-un remains off, for now. But the president suggested that he might reverse course again. Especially after the surprise meeting between Kim and South Korean President Moon Jae-in, anything seems possible. A Trump-Kim tête-à-tête could fail spectacularly, but it would offer an opportunity to reduce tensions on the peninsula and perhaps even advance the objective of eliminating the North’s nuclear arsenal.

Most American policymakers desire the end of the Kim dynasty, if nothing else because of its crimes against the North Korean people. However, the most critical issue facing the U.S. and Northeast Asia is the prospect of the DPRK expanding its nuclear arsenal and extending the range of its missiles. Resolving that issue would increase opportunities to engage the North over human rights. Failing to satisfy the two sides’ respective security concerns would make progress in other areas unlikely.

Any meaningful agreement, especially one which meets the administration objective of speedy denuclearization, will require U.S. concessions. But so far the administration position appears to be that the Democratic People’s Republic of Korea should disarm, hoping to receive generous but as yet undetermined benefits. That includes on the crucial issue of security, even though the last dictator to trust Washington after disarming, Libya’s Muammar Gaddafi, ended up dead at the hands of a street mob. Pyongyang’s outburst, which led President Trump to cancel the summit, appeared to be the DPRK saying that it would not be played.

The Trump administration and its ally South Korea have offered verbal assurances, such as Secretary of State Mike Pompeo’s statement that he does not desire regime change and the president’s promise that Kim will be “very, very happy.” Little better are the paper guarantees on offer, such as a peace treaty to formally end the Korean conflict. The plea appears to be to “trust us.”

However, Kim, despite his relative youth, is no impressionable naïf, likely to be moved by the president whispering a few sweet-nothings into his ear. At age 27 Kim took over a venerable dictatorship, eliminated a gaggle of more experienced rivals, and even brutally purged family members.

What could the U.S. offer? The most visible American military threat and important symbol of U.S. intervention is the troop presence in South Korea, along with the underlying security alliance. The latter was formed in the aftermath of the inconclusive end of the Korean War. Despite massive changes on the Korean peninsula in the intervening 65 years, America’s security guarantee remains. The current 28,500 personnel are but the proverbial tip of the iceberg of Washington’s military commitment to the Republic of Korea.

This policy risks war, since it is meant to ensure America’s involvement in another Korean conflict. The Cold War might have made the peninsula vital to America in 1950, but that is no longer the case in 2018. Indeed, there is no military need for the U.S. in the Republic of Korea. Author Steven Metz observed that “Even if diplomacy does not pan out, South Korea has reached the point that militarily where it could defeat another North Korean invasion on its own.”

America’s commitment also is expensive. The principal cost is not for bases, which South Korea helps offset, but raising and equipping additional units for a major war contingency. Noted Metz: “For the U.S. military, disengagement from South Korea would dramatically lessen the need for land forces in the Asia-Pacific. While the United States would still need robust air and naval capacities, its ground forces would be relegated to contingency operation and training missions. This could lead to major force cuts in the U.S. Army.”

In other words, withdrawal would be win-win.

So what better way to provide Kim with regime security than to offer to end America’s military commitment to the ROK if the North abandons its nuclear weapons?

Some question whether Pyongyang desires a U.S. exit. Kim had not made such a request, either to Secretary of State Mike Pompeo or South Korean President Moon Jae-in. Both appear to take his silence as a preemptive concession. Moon opined that North Koreans “only talk about an end to hostilities against their country and about getting security guarantees.” However, what do they mean by the latter? South Korean officials admitted that Pyongyang had not defined the term. Nor did the summit declaration.

In fact, the lack of a formal request is virtually meaningless since the detailed negotiations were yet to begin. At the summit and subsequent meetings Kim and his officials were more likely to turn their oft-reiterated demands for security assurances and the end of America’s hostile policy into specific proposals. Seven years ago Pyongyang issued a statement discussing steps necessary to end America’s “hostile policy,” which included withdrawing U.S. forces. Kim, who worked so hard to consolidate power, was never likely to risk a Libya-denouement.

Most analysts seemed skeptical that Kim had dropped the issue. Stephen Walt said he wouldn’t bank such a North Korean promise. Lisa Collins of the Center for Strategic and International Studies expected a request for “the eventual withdrawal of U.S. forces from the Korean Peninsula.” John Nilsson-Wright of London’s Chatham House warned that Pyongyang may press for withdrawal of American troops not only from the Korean peninsula, but also “further afield in East Asia, especially within Japan.”

North Korea’s silence on troop withdrawals also might have been meant as a signal to China, which views America’s presence as another measure to contain its rise. By ignoring the issue Kim may have alerted Beijing that it cannot rely on the DPRK to defend the former’s interests. At least, without providing something in return.

Relations between the two nominal allies have frayed badly in recent years. Most notably, President Xi Jinping steadily tightened sanctions and enforcement against the North and refused to meet Kim, even while repeatedly dealing with South Korean President Park Geun-hye. The prospect of the People’s Republic of China being isolated from potentially dramatic developments on the peninsula, perhaps reinforced by Kim’s silence on such an important issue, apparently impelled Beijing to invite the North Korean leader to China twice in two months. That contact, backed by promises of PRC support, could have made Kim more likely to press the issue at the summit.

Of course, as suggested by Euan Graham of Sydney’s Lowy Institute for International Policy, Kim might prefer to pursue withdrawal indirectly, eliminating “the rationale for maintaining forces on the Korean Peninsula.” Or Pyongyang could decide that it prefers the presence of a small U.S. garrison to keep America engaged in Northeast Asia as a counterbalance to North Korea’s neighbors, including China.

After all, the Kim dynasty played the Soviet Union against the PRC during the Cold War.

Kim Jong-il reportedly told South Korean President Kim Dae-jung and Roh Moo-hyun at their respective summits that full withdrawal was not necessary. When I visited Pyongyang last year, North Korean officials emphasized their desire to avoid excessive economic dependence on any single nation.

Still, this wouldn’t necessarily mean that Kim Jong-un wants American military forces close. And his desire to preserve America’s presence would not be a good reason for Washington to do so. To the contrary, a North Korean request that the U.S. advance the Kim dynasty’s interests would seem to be a good argument for expeditiously pulling out.

If the North ended up demanding a U.S. withdrawal, that would seem to be a small price to pay for eliminating Pyongyang’s nuclear arsenal. Yet some analysts say no. They appear to believe that it is more important to preserve the U.S. garrison on the Korean peninsula than to rid the same territory of nuclear weapons.

For instance, an anonymous South Korean official told Reuters: If the North raises the issue of withdrawing American forces, “things could get ugly quickly despite the summit.” Hopefully, the official added, they will “present something more realistic.” The University of Maryland’s Naoko Aoki insisted that such a demand would be “a nonstarter for the United States.” Patrick Cronin of the Center for a New American Security declared, “You don’t want the president to sign away the alliance.”

Academic and author Van Jackson warned against “playing North Korea’s game.” He worried about “decoupling,” by which the North would agree to only limited denuclearization, abandoning the ability to target America but not its neighbors. Even if the U.S. did not immediately leave, there would be “debates in Seoul about the future of the alliance, and with a peace treaty in hand, anti-American activists in the South will have a much stronger case for pushing out the United States than in decades past.”

Thomas Wright of Brookings similarly warned that the North might attempt to trade a verifiable nuclear freeze for withdrawal, which “would be widely regarded as an unmitigated disaster for the United States. It would trade one of America’s most important alliances” and “legitimize” the North’s “existing arsenal.”

Former Pentagon official Kelly E. Magsamen declared: “U.S. presence in South Korea is a sacrosanct part of our alliance,” which presumably also is sacrosanct. Most explicit was retired South Korean General Shin Wonsik: “For South Korea, living with a nuclear-armed North Korea is much better than living without American troops.” Why? “If they are gone, we will lose proof that the Americans will defend us. We will lose confidence that if war breaks out, we can win.”

That sounds like the Republic of Korea of 1950.

Admittedly, the DPRK has a large army. Bruce Klingner of the Heritage Foundation warned: “Even if you address the nuclear missile, chemical and biological threat, you still have a million-man army in North Korea, forward deployed near the Demilitarized Zone with mechanized corps, armored corps, and artillery corps in an offensive, not defensive, posture.” He claimed that merely raising the possibility of withdrawal would exacerbate concerns over America’s “commitment and resolve” to defend its allies.

Yet the ROK can easily, if not necessarily cheaply, solve this problem. South Korea has busted into the globe’s top dozen economies, and is well able to defend itself. The South possesses around 45 times the GDP and twice the population of its northern antagonist. Even with today’s military, configured in expectation of massive American reinforcement, Seoul probably would defeat a North Korean attack. Noted writer Ramon Marks: “Outdated equipment, limited logistical capabilities, and reports of starving North Korean troops, ransacking farmer homes searching for food, hardly supports the image of a juggernaut force.” And South Korea could do so much more than it does now.

No surprise, Seoul opposes any withdrawal. The ROK benefits from immense American defense subsidies, allowing greater resources to be invested in economic development. South Korean presidential spokesman Kim Eui-kyeom went so far as to state that the troop presence “has nothing to do with signing peace treaties,” even though American forces originally came to fight a war, which legally has not ended.

Nevertheless, there are realists even in the South. Moon Chung-in recently acknowledged that “It will be difficult to justify their continuing presence in South Korea” after a peace treaty is approved. Similarly, argued Lee Byong-chul, of Seoul’s Institute for Peace and Cooperation, “if a peace treaty is signed, the U.S. troops are bound to peter out. Much of the reason they are staying here will be gone.” Harvard’s Stephen Walt acknowledged the same point.

Opposition from Americans is more difficult to fathom. For many policymakers the alliance has gone from means to end. Although it lost its raison d’être when the ROK gained the ability to protect itself, policymakers have discovered a gaggle of new goals.

Some alliance proponents contend that other potential aggressors lurk nearby. However, the only plausible threats are China and Japan. The former wants influence, not conquests, and Seoul is unlikely to join America in combat against the PRC in any contingency other than an attack on the ROK. An invasion by Japan is only slightly more plausible than one by Mars. Another fear is that business and investment would flee the South. Unlikely if the ROK stepped up to fulfill its responsibilities.

Would withdrawal signal American retreat from Asia, with the vacuum being filled by malign actors, presumably China and Russia? Similar fears were advanced when the U.S. left Vietnam, yet Washington continued to dominate the region. Washington always has exercised discretion in how and where it engaged Asian nations. Moreover, friendly states should play a more robust regional role, constraining if not containing the People’s Republic of China, the only serious challenger to allied interests.

Critics worry that an arms race might erupt. Better for friendly states to spend more in their own defense than Washington forever maintain an oversize military unnecessary for America’ defense. Would the Japanese fear being similarly “abandoned” by the U.S.? Turning defense responsibilities back to capable parties after decades of support is not abandonment, and Tokyo, too, should be doing far more. Which triggers another concern, that other countries would fear a rearmed Japan. In fact, Tokyo’s neighbors increasingly welcome a more active Japanese policy to confront China.

Are bases in Korea necessary for U.S. military operations in the region? Washington can retain a relationship, since permanent garrisons are not necessary for advantageous military cooperation. Worse in the view of some, South Korea and Japan might go nuclear. Yet isn’t that better than them being vulnerable to foreign threats or the U.S. having to risk nuclear war on their behalf?

In fact, Wright unintentionally made an argument for withdrawal when he complained that pulling out “would signal that the United States cares little for its friends and is only concerned about direct threats to the homeland.” But should not those who lead the U.S. pay most attention to threats against America, especially the possibility of nuclear attack? And which of Washington’s friends cares more for the U.S. than themselves?

In fact, despite his staff’s support for the status quo, the president continues to doubt current policy. For instance, NBC reported that White House Chief of Staff John Kelly argued with President Trump, who had proposed ordering home America’s troops. The New York Timesreported that the White House tasked the Pentagon to consider withdrawal options. These two stories were denied all around, but even after insisting that a pull-out was not “on the table,” President Trump added that “I have to tell you, at some point in the future I would like save the money.” An anonymous official told CNN that withdrawal was viewed as a possible consequence if full denuclearization is achieved.

The president long has been skeptical of what amounts to defense welfare to prosperous and populous allies. In 2013, before running for president, Trump asked “How long will we go on defending South Korea from North Korea without payment.” Two years later candidate Trump complained that “We get practically nothing compared to the cost of this.” In 2016 he argued that “We’ve got our soldiers sitting there watching missiles go up” and “You say to yourself, ‘Well, what are we getting out of this?’”

Just two months ago he mused: “We lose money on trade, and we lose money on the military. We have right now 32,000 soldiers on the border between North and South Korea. Let’s see what happens.” He also complained that America gets “practically nothing” for the $1.2 billion cost to station forces on the peninsula. (In fact, as noted earlier, the real cost is far higher.)

Moreover, Defense Secretary Jim Mattis seemed open to a pull-out, merely observing that America’s presence is “part of the issues that we’ll be discussing in the negotiations with our allies first and, of course, with North Korea.” After the flurry of official denials he backed away, though not too far: “That’s not something that would be on the table in the initial negotiation” but would depend on denuclearization. For “the foreseeable future, our presence in Korea is not a negotiable issue,” he told a Senate hearing.

President Jimmy Carter talked withdrawal and faced irresistible opposition from his own appointees. Deputy Assistant Secretary of Defense for International Security Affairs Morton Abramowitz later admitted: “we began a rearguard action — delay it, water it down, mitigate the decision as much as possible.” Some officials said the idea was a good one, but just not yet. For instance, Gen. John Vessey, Jr., head of U.S. Forces in Korea, declared that “President Carter’s decision is based on a vision of the future, a Korea four or five years from now in which United States ground troops won’t be required.” But every future proposal for withdrawal was met with similar pronouncements, putting the appropriate moment always just beyond reach.

After decades of military involvement on the Korean peninsula, America’s presence has become an important card to play in negotiations with North Korea, whether at a summit or in other negotiations with Pyongyang. Surely eliminating nuclear weapons from North Korea is more important than maintaining an outmoded troop presence in the South.

If the DPRK ends up proving indifferent to the presence of American soldiers, then Washington should simply withdraw the troops as a matter of course. After 68 years on the Korean peninsula, it is time for American forces to come home.

Doug Bandow is a Senior Fellow at the Cato Institute and 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.