The United States and South Korea are finding it harder and harder to stick to the same playbook on North Korea. Consider what’s happened just in the month since North Korean leader Kim Jong Un and South Korean President Moon Jae-in met in Pyongyang for a landmark summit.

In early September, the South opened a liaison office with the North, reportedly without first informing the U.S., which opposed the move. South Korean Foreign Minister Kang Kyung-wha later publicly admonished Washington for its purported inflexibility on the good faith measures Pyongyang demanded. The next week, Kang said that Seoul was considering lifting sanctions on North Korea related to its sinking of a South Korean ferry in 2010. Another senior South Korean official walked back the claim, but not before U.S. President Donald Trump said Seoul “does nothing without our approval,” a comment that riled the Korean public. On Oct. 12, South Korea’s new military chief pledged to push for the transfer of wartime operational control, or OPCON, over his country’s forces from Washington – which has held it since the Korean War – back to Seoul. The U.S. State Department expressed concern a few days later over plans to connect road and rail links between North and South Korea as early as next month. And on Oct. 18, Reuters reported that Washington was pressuring Seoul to abandon plans with Pyongyang for a no-fly zone over the Demilitarized Zone.

These disagreements have brought thorny issues over the shape and size of the U.S.-South Korea alliance back to the surface. They don’t spell the imminent end of the partnership; allies squabble, short-term interests diverge, and political forces make mountains out of molehills – especially when one side of a partnership has troops on the other side’s soil and each could start a war the other may not want. So long as an alliance is rooted in firm strategic logic, these things generally don’t matter. But in the case of the U.S. and South Korea, the strategic logic is starting to crack, and Seoul has little choice but to defy Washington where it must to prepare for the day when it may have to strike out on its own.

Different Means to Different Ends

U.S. and South Korean interests in exactly how nuclear negotiations with North Korea would play out were never going to align neatly. Though both would like Pyongyang to fully disarm, they disagree on the odds for achieving that outcome and, more important, on what’s at stake if the North doesn’t capitulate. Seoul thinks denuclearization is a long shot, at best, and has resigned itself to living with a nuclear neighbor. North Korea already has the missiles and artillery necessary to lay waste to South Korea, a threat it relies on as its primary deterrent to invasion. Seoul’s most pressing interest, then, is to keep the U.S. – a target Pyongyang cannot yet reliably strike – from starting a war in which it would bear most of the risk. That’s why South Korea was so quick to claim the role of mediator between the U.S. and North Korea once Pyongyang signaled a willingness to talk at the start of the year. To keep Washington on board with the process, Seoul is touting the sincerity of Pyongyang’s denuclearization promises and facilitating dialogue. To keep Pyongyang on board, meanwhile, Seoul has been dangling incentives, modestly pulling back its defenses and emphasizing that the diplomatic process it is leading is the main force keeping U.S. military action at bay.

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South Korea has bought itself some time with this strategy, but it hasn’t brought North Korea any closer to disarming. And so long as the U.S. is still pushing for North Korea’s complete, verifiable and irreversible denuclearization, Seoul’s outreach to the North will weaken Washington’s hand. Even if the U.S. can’t persuade North Korea to give up its nukes without going to war, it still has other ways to discourage Pyongyang from moving forward with its long-range missile program – the one North Korea needs to truly put the American homeland at risk – and to shape the country’s behavior as a nuclear power. Nevertheless, now that its threat of war is off the table, at least temporarily, and now that China and Russia are finding less and less reason to keep up sanctions pressure, the U.S. is losing its leverage.

Pyongyang has demonstrated an extraordinary pain tolerance over the decades, and the U.S. needs all the pressure it can muster to get North Korea to make a deal. That’s why Washington balked at Seoul’s mention of lifting even sanctions entirely unrelated to North Korea’s nuclear program. It’s also why it seems to be balking at the plans to establish a no-fly zone over the DMZ. For years up until this spring, the U.S. routinely flew bombers from Guam over the region to try to probe for weaknesses in North Korea’s air defenses and to remind Pyongyang of its willingness and ability to deal with the nuclear issue by force. Washington doesn’t want the North to think it’s in the clear just yet.

Preparing for the Eventualities

Ultimately, if the U.S. were to deem it necessary to go to war with North Korea, South Korea could do little to stop it. Seoul’s situation today underscores a historical reality for the Korean Peninsula: It has always been in danger of becoming a pawn in the games of foreign powers. Since the peninsula’s partition, when both North and South became wholly dependent on outside powers for their defense needs, that danger has become only more acute. It’s a position that has required constant, nervy maneuvering from both governments to prevent their security from being sacrificed for that of their patrons.

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In light of their vulnerability, South Korea has a long-term imperative to pursue reunification with the North. Made whole again, Korea would become one of East Asia’s strongest military powers, finally capable of looking outward rather than primarily across the 38th parallel, and it would obtain a freedom of action that it hasn’t enjoyed in centuries. The odds of reunification happening quickly, if at all, are slim. But the process has to start somewhere, and it won’t start at all if the North is in full isolationist mode. Pyongyang won’t take the small but risky reciprocal steps necessary to normalize relations with Seoul if it feels doing so would expose it to attack from the U.S. or the South. And Kim won’t pursue any sort of confederation until he can pick up some momentum toward narrowing the gap in economic development between the two Koreas. Considering its immediate and more distant goals, Seoul is keen to move first and quickly to try to draw Pyongyang out of its defensive shell with tangible incentives and to give it a taste of the economic fruits international integration has to offer.

Reunification would almost certainly require a radical redefinition of the U.S.-South Korea alliance, if not its end. Of course, Seoul is in no position to break away from Washington at present. The detente with Pyongyang is still far too fragile for South Korea to feel comfortable without U.S. military might on its side, especially now that North Korea’s nuclear arsenal can offset some of its own conventional advantages. Hawkish factions at home will also keep the current South Korean government and its successors from drifting too far from the U.S. Furthermore, the U.S. pressure on the North is working in South Korea’s interests in some ways, serving as the stick to Seoul’s carrots.

The debate over OPCON reflects South Korea’s ambivalence. Seoul has pushed for the transfer repeatedly in the past, and Washington has generally been open to it. After all, the U.S. doesn’t need forces in South Korea to enforce its core interests in the Western Pacific, and it is eager for its allies across the globe to take on heavier shares of the joint security burden. Yet the target dates for the OPCON transfer have come and gone time and again – in 2009, 2012 and 2015. The postponements are due in part to the many sticky issues the U.S. and South Korea would have to sort out ahead of the transfer; the last thing either side wants is a command structure in flux when war is still a real possibility. But the primary reason is that Seoul has never felt quite comfortable with the idea that U.S. troops might leave the peninsula altogether after the OPCON transfer – perhaps before South Korean forces were ready to stand on their own. (The U.S. defense secretary and his South Korean counterpart agreed on Oct. 19 to take another shot at the OPCON transfer at “an early date.”)

South Korea’s misgivings aside, the past two years have put the perils of overreliance on the U.S. in stark relief. Unlike in previous discussions of the OPCON issue, moreover, Seoul now sees an opportunity to start mending ties with Pyongyang for good. And so, South Korea is doubling down on preparations to go its own way. Preparing for the end of an alliance isn’t the same thing as pushing for it, though. It’s just a recognition that seismic shifts in the region are always a possibility.

Phillip Orchard
Phillip Orchard is an analyst at Geopolitical Futures. Prior to joining the company, Mr. Orchard spent nearly six years at Stratfor, working as an editor and writing about East Asian geopolitics. He’s spent more than six years abroad, primarily in Southeast Asia and Latin America, where he’s had formative, immersive experiences with the problems arising from mass political upheaval, civil conflict and human migration. Mr. Orchard holds a master’s degree in Security, Law and Diplomacy from the Lyndon B. Johnson School of Public Affairs, where he focused on energy and national security, Chinese foreign policy, intelligence analysis, and institutional pathologies. He also earned a bachelor’s degree in journalism from the University of Texas. He speaks Spanish and some Thai and Lao.