Trump is at least challenging a bizarre status quo that assumes the U.S. must forever protect prosperous and populous allies.The U.S. and South Korea have deadlocked in negotiations over Seoul’s payment to support American forces. President Donald Trump demanded a fivefold increase. Shocked South Korean officials refused the administrations demands, which some observers called blackmail. If the two sides fail to agree, Washington has said it will furlough the 9,000 South Koreans who work for the U.S. military at the end of the month.

Unorthodox, perhaps, but a succession of presidents have pressed for greater burden-sharing with little effect. Washingtons allies had come to believe that American policymakers were determined to intervene abroad irrespective of costs. So Washingtons requests were routinely ignored. No longer.

Prior to the end of World War II, American officials thought very little of the Korean peninsula. But Japans defeat left the Hermit Kingdom up for grabs. A Japanese colony with Chinese communist forces and Soviet armies along its border, Korea could have been easily absorbed by Joseph Stalin. However, he agreed instead to divide the peninsula. The occupation zones turned into separate countries, each of which claimed to represent the entire peninsula.

Backed by Beijing and Moscow, the Democratic Peoples Republic of Korea invaded the South on June 25, 1950. The U.S. intervened, and by Thanksgiving, an American victory seemed imminent, but then the Peoples Republic of China sent its forces in. The battle line settled close to the original border, with more than two years of static defense to follow. An armistice was finally agreed to in July 1953.

That did not end Americas military role, however. The South had been ravaged by the war. The ROKs aged, irascible president, Syngman Rhee, offered little political stability. So the U.S. inked a mutual defense treaty that turned South Korea into a formal security dependent.

China brought its troops home a few years later. Rhee was overthrown in 1960 and ultimately succeeded by General Park Chung-hee, who set the South on a path of rapid economic growth. After much hardship and bloodshed, democracy came to the ROK in 1987. The South soon outpaced its northern antagonist on virtually every measure of national power. Maos death and Beijings reform course ended Chinese military support for the North. The collapse of the Soviet Union cost the DPRK its other ally.

The Souths military was better trained, equipped, and supported. Only in quantity of men and materiel did North Korea retain a lead. That, however, was a matter of choice. The ROK could afford to match the North in any way it thought necessary. But doing so wasnt necessary since Seoul could count on Washington to do the dirty work in another big war.

Of course, South Koreans enjoy their good deal: the globes superpower promises to go to war on their behalf, even insisting it will use nuclear weapons if necessary. Seouls job? Agree to be defended.

Not exactly a mutual defense treaty, as claimed. Indeed, Washington treats the South like a child. It retains operational control of the South Korean military in wartime, an extraordinary concession of sovereignty.

Defense Secretary Mark Esper was right to argue that Shouldering the cost of our common defense cannot fall disproportionately to the American taxpayer. As he and Secretary of State Mike Pompeo explained in a joint article, basing costs are only one part of the picture. Americas contributions to South Koreas defense in this highly technological ageincluding some advanced capabilities Seoul still needs to acquirefar exceed the cost of U.S. boots on the ground and constitute a far larger burden for the American taxpayer than meets the eye.

None of the arguments for treating defense as welfare are persuasive. One is that basing troops in the ROK saves Washington money, since Seoul covers part of the cost$870 million last year in the Special Measures Agreement. However, the alliance requires a bigger U.S. military. Every additional defense promise requires more forces. That is, military spending is the price of Americas foreign policy.

South Korean Defense Minister Jeong Kyeong-doo argued that his country has made contributions beyond the SMA, like increasing the ROK defense budget and spending on American weapons. But Seoul should arm itself as a matter of course.

Another claim is that America gains important benefits, that the purpose of the alliance transcends the Souths security. For instance, Kyle Ferrier of the Korea Economic Institute of America cited intangibles, contending that the alliance enhances deterrence of North Korea, encourages South Korea to adopt U.S. foreign policy positions, and supports common values in the Indo-Pacific.

However, Seouls and Washingtons interests would generally align without an alliance and risking war is a costly way to enhance policy support. The ROK also is capable of deterring the North.

Most importantly, Americas tripwire ensures that it will become involved in any conflict. As North Korea develops nuclear weapons and long-range missiles, the cost of this arrangement grows exponentially. In March, Esper told Congress that U.S. intelligence believed the North could target Hawaii, threatening our homeland with nuclear and ballistic missile capabilities.

Esper advocated a force posture to deter and defend against these threats, as well as Pyongyangs extensive conventional forces. Much better, however, would be withdrawal, since the DPRK targets America only because it’s threatening the North. North Korea isnt suicidal and wont attack Americaunless the U.S. is threatening the Kim regime with destruction. And nothing on the peninsula is worth risking the American homeland.

Alliance advocates also envision South Korea contributing to a system to contain China. In fact, even before the Chinese Communist Party bungled its response to the coronavirus epidemic, China was facing significant economic, demographic, and political challenges. More important, the likelihood that the South would back America in war against Beijing that did not involve the ROK is virtually zero. No South Korean government leader would make China into a permanent enemy to, say, help Taiwan or the Philippines.

Still, the presidents policy seeking to end Seouls sweet deal looks unseemly to some. Columnist Hal Brands complained that Trump was weakening alliances by trying to extract as much money as possible from countries that depend on Washingtons protection. The administrations demand has been called a blatant shakedown and protection racket. Yet the South is not entitled to American protection.

Esper did soften the presidents demand, advocating the increase in order to reach a mutually beneficial and equitable agreement that will strengthen the alliance and our combined defense long into the future. Unfortunately, in doing so, American officials abandoned the biggest stick: if South Korea balks, they say there is no intention to bring U.S. forces home. Our commitment to the defense of the Republic of Korea is ironclad said U.S. Ambassador Harry Harris. Which means Washington has abandoned its only serious leverage.

All that is left is the furlough, which will hurt South Korean employees but few others. And someone will have to perform those tasksprobably American uniformed military personnel. Which would effectively increase existing military manpower requirements.

The furlough threat has not impressed Seoul. A recent poll found that just 4 percent of South Koreans would pay billions more for Americas support. A majority suggested cutting the number of Americans stationed in South Korea if an agreement was not reached.

Sukjoon Yoon, a retired South Korean naval officer, argued, There is growing support among younger South Koreans for a more autonomous defense policy: if the United States wants to withdraw its troops from the Korean Peninsula, then that is fine by them. If the Souths population doesnt believe American military personnel are needed, why are they there?

Rather than hire out American’s armed forces like mercenaries, Washington should simply set a withdrawal timetable, set in conjunction with South Korean officials, to ensure a smooth transition. The ROK could then decide how much to spend on its military without badgering from America. Seoul might even decide to go nuclear, since its confidence that the U.S. would risk the homeland to protect South Korea is more fantasy than reality.

If the Trump administration wont put Americans first by shedding unnecessary defense burdens, a distant second best is having allies, such as the South, pay more. After all, Washington is essentially bankrupt, set to run trillion dollar deficits for years to come. The numbers will only worsen as the retired population continues to swell. At some point, domestic political support for subsidizing foreign governments that dont want to pay their way is going to collapse. Better to make an orderly transition now than to be forced to act in the midst of a fiscal crisis.

The American-South Korean alliance made sense when it was forged. But the world has moved on. Even when President Trump does the right thing, he does so badly. Still, he’s the only president challenging a bizarre status quo that assumes Americans must forever protect prosperous and populous allies. It truly is time for a change.

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