On his recent visit to the South, Secretary of State John Kerry proclaimed: “The United States will, if needed, defend our allies and defend ourselves.” When the alliance was created those two objectives were considered to be one: Washington forged alliances to protect itself. Alliances were a means to an end.

Today alliances have become an end. Allies are defended even when doing so does not advance American security. Six decades after the end of the Korean War, the U.S. maintains 28,500 troops on the peninsula. American personnel act as a tripwire to ensure Washington’s involvement if the so‐​called Democratic People’s Republic of Korea invaded the South. But the war would involve the entire American military, as evidenced by the recent flyover by B-2 bombers and F-22 stealth fighters, intended to intimidate the DPRK.

The cost of the commitment is high. Every promise to go to war forces Washington to create corresponding military assets. The Obama administration is further reinforcing America’s East Asian security guarantees with the so‐​called “pivot” or “rebalancing.”

Worse is the risk of war. Korea mattered to the U.S. in 1950 because it occurred early in the Cold War. Washington authorities perceived the DPRK invasion as the first round of Soviet‐​inspired aggression. In fact, the conflict mattered more for its impact elsewhere than on the peninsula.

Today the situation is reversed. The White House recently called the alliance “a linchpin of peace and security on the Korean Peninsula and in the Asia‐​Pacific.” That may be the case for the ROK, but not for America. A new Korean war would have awful economic and humanitarian impacts, but there would be minimal effect on America’s security. A North Korean attack on the ROK would be a North Korean attack on the ROK, not the prelude to global war.

Moreover, South Korea is well able to defend itself, in contrast to 1950. Even if Seoul is improbably believed to be an essential ally, it does not require U.S. defense subsidies.

The U.S.-ROK relationship also interferes with allied relations with China. Beijing perceives, not unreasonably, an American‐​led effort at containment. Washington’s insistence that U.S. troops based in the South are “dual use” and thus available for contingencies elsewhere in East Asia—mostly involving the People’s Republic of China—further inflames Chinese suspicions.

The issue may encourage the residents of Zhongnanhai to devote more resources to the military. The policy also discourages cooperation regarding the North. Beijing wants stability on the peninsula, but does not desire a reunified Korea, allied with America, hosting troops on China’s border. The PRC worries far more about an American attack than a North Korean attack. Thus, the tighter America clings to the alliance and the more expansive Washington attempts to make the alliance, the less likely the PRC is to take any steps which would undermine North Korea.

The alliance also brings the U.S. into conflict with the North Korean regime. Michael Auslin of the American Enterprise Institute advocated the Washington begin “to think about regime change,” but there’s little the U.S. can do to bring that about, desirable though it would be. Better to leave the challenge of dealing with Pyongyang with the DPRK’s neighbors.

Absent America’s military involvement on the peninsula, Washington wouldn’t even need a North Korea policy. The North is an impoverished wreck which suffered from mass starvation less than two decades ago. Pyongyang has no means to hurt the U.S.

Even if the North eventually produces a long‐​range missile, develops accurate targeting systems, creates nuclear weapons, and miniaturizes warheads, it still would be suicidal for Pyongyang to attack the world’s premier military power. North Korea is focusing its ire on Washington only because the U.S. is involved on the peninsula. Washington could treat the DPRK like it dealt with the Soviet Union and the latter’s Warsaw Pact allies—with reluctant diplomatic and limited economic relations.

The alliance also is costly for the ROK, subjecting South Korean security to American control. Washington will never treat a defense client as an equal. After all, Seoul’s actions could trigger a war involving America.

For instance, in March the ROK military threatened “strong and stern measures” in response to any North Korean attack. However, retaliation against a North Korean provocation could escalate to war. Washington rightly insists on consultation if not veto power.

Decades ago American officials stopped the South’s nascent nuclear program. The U.S. currently limits the range of South Korean missiles despite the DPRK’s missile development. Washington has a 39‐​year‐​old agreement with the ROK preventing the latter from reprocessing spent nuclear fuel. Seoul voluntarily accepts these restrictions because of pressure from its principal ally. Even though, complained Chung Mong‐​joon, a leading business and political figure—and past presidential candidate—“Telling us not to consider any nuclear option is tantamount to telling us to simply surrender.”

These restrictions have grown more galling for a prosperous and vibrant democracy in which nationalism is rising. However, the ROK has no complaint since it could take over its own defense, including operational command of its own forces (now scheduled for 2015).

South Koreans also pay for America’s large‐​scale military presence. This year will see negotiations over the latest Special Measures Agreement, which includes host nation support, covering around 40 to 45 percent of America’s cost for stationing its troops. A Status of Forces Agreement limits ROK control over U.S. military personnel. That SOFA created a crisis in relations in 2002 after a traffic accident involving a U.S. Army vehicle killed two teenage girls.

Even the ROK’s policy toward North Korea is a hostage of the alliance. The country with the most at stake obviously is the South. However, as Seoul’s Big Brother providing security, Washington is intent on influencing South Korean policy. After all, a mistake by Seoul could mean war for America.

Yet the South cannot assume the U.S. guarantee is forever, especially given Washington’s budget crisis. Chung advocated that the ROK build its own nuclear weapon for this reason: “At a time of crisis, we are not 100 percent sure whether the Americans will cover us with its nuclear umbrella.” And he’s right. Whatever Washington’s present intentions, they could change, and South Korea may find its fate in another nation’s hands. As Chung observed in an address published by Seoul’s Asan Institute, “Korea always came as an afterthought for U.S. policy makers.”

Moreover, the growing attempt to give the alliance a regional or even global role threatens to entangle the ROK in wars in which it has no interest. Worst would be conflict with China over Taiwan or various East Asian territorial disputes. Moreover, Seoul has sent troops to Vietnam, Afghanistan, and Iraq to help ensure Washington’s continued commitment.

Finally, one of the most important impacts of the alliance, on both America and the South, is to enable and even encourage the ROK to try to appease the North. Seoul long has underfunded its defense, allowing the North to enjoy a quantitative if not qualitative military advantage. The South also is pushing a “global South Korea” policy, adapting its force for a more active international presence.

Moreover, for a decade South Korean Presidents Kim Dae‐​jung and Roh Moo‐​hyun followed the so‐​called Sunshine Policy, providing roughly $10 billion worth of cash, food, and other aid to the North. Although many transfers ended after the election of President Lee Myung‐​bak in 2007, South Korea continued to operate the Kaesong Industrial Complex, home to 123 ROK companies employing 53,000 North Koreans and pumping at least $90 million annually into the DPRK economy. After Pyongyang suspended KIC operations as part of its latest campaign of provocation, the South conducted its latest campaign of begging to reopen the facility.

Even after the North sank a South Korean navy vessel and bombarded a South Korean island in 2010, Seoul did essentially nothing. Indeed, in the 2012 election the South Korean electorate pushed all candidates to advocate a more accommodating approach to the North.

Park Geun‐​hye won the election and indicated that Seoul could never accept a nuclear North Korea and would “no longer tolerate” DPRK military strikes. However, she also advocated expanding the KIC, reducing restrictions on commercial ties with the North, and decoupling humanitarian aid from political issues. In principle, she expected to improve ties in response to a positive North Korean response. She explained: “South Korea should adopt a policy of ‘trustpolitik,’ establishing mutually binding expectations based on global norms.”

Unfortunately, there is no evidence that the North is interested in meeting global norms. Even if it does not respond, the Park government still will feel pressure to promote better relations. Especially if Pyongyang follows past practices by offering small concessions mixed with positive promises.

This policy obviously is no bargain for America: the South underwrites the military of the nation against which the U.S. is prepared to go to war. In return, Washington receives marginal assistance from the ROK in conflicts the U.S. should not be fighting.

The strategy looks equally dubious for the South. Complained Edward Luttwak, “South Korea has matched the North’s bellicosity with its own strategic perversity: It remains obsessed with an utterly unthreatening Japan and has been purchasing air power to contend with imagined threats from Tokyo as opposed to the real ones just north of the demilitarized zone. Seoul is simply unwilling to acquire military strength to match its vastly superior economy.”

Even so, the decision should be Seoul’s alone—if America was not defending the South. Washington has reason to object to being asked to defend the ROK from an enemy which the ROK is subsidizing. If Seoul responds that the subsidies don’t matter because the DPRK poses no threat, then U.S. military support is unnecessary.

Of course, Washington cannot force the ROK to change policy, though the House Foreign Affairs Committee is considering legislation urging Seoul to close the KIC. Luttwak suggested that “The price of continued U.S. protection should be the adoption of a serious defense policy, the closure of the Kaesong racket, and a complete end to cash transfers to the North, whatever the excuse.” Better would be to end the unnecessary protection for the South, leaving the latter to make its own choice.

Can and should the alliance, which marks its 60th anniversary this year, survive? While South Koreans’ desire for a cheap defense ride might override their nationalistic desire to be treated as equals, the U.S. gains no comparable benefits for entangling itself in the Korean imbroglio. The alliance made sense for Washington six decades ago, but not today.

Americans should laud the alliance for a job well done. And emphasize the cultural, family, and economic ties which continue to bind the two peoples. But Washington should leave Seoul to take over responsibility for South Korea’s defense. If the ROK wants to be treated like a grown‐​up, it should act like one.