Editor’s note: North Korea test-fired another missile that flew over Japan and crashed into the Pacific Ocean on Sept. 14, just as the one test-fired in late August had. Early evidence suggests it, also like the one before it, was a Hwasong-12 intermediate range ballistic missile, not an intercontinental ballistic missile. South Korea has since test-fired a ballistic missile of its own.

The same day, the commander who oversees U.S. nuclear forces said he was operating under the assumption that the hydrogen bomb Pyongyang claims to have tested on Sept. 5 was indeed a hydrogen bomb, citing the size of the blast as a compelling enough reason to do so. The Sept. 5 test made us rethink some assumptions of our own – specifically that North Korean and the United States would eventually come to blows and that South Korea would enter the fray in spite of the causalities it would inevitably incur. In light of these developments, we republish our Reality Check from Sept. 5, in which we considered an alternate theory – and how that theory would affect the balance of power in East Asia for years to come.

By Jacob L. Shapiro

This past weekend, when most Americans were celebrating their Labor Day holiday, North Korea was all business. On Sunday, the government in Pyongyang tested a hydrogen bomb, and though it’s never clear how these kinds of tests fare, the seismic activity and the reactions from the U.S. and Japan suggest it was a success. Pyongyang threw down the gantlet, and the message was clear: The United States will either have to accept North Korea as a nuclear power, or it will have to destroy North Korean nuclear facilities while it still can.

The test took most of the world – and, admittedly, us at GPF – by surprise. Our assessment of the situation wasn’t particularly rosy, but we didn’t think it would deteriorate so quickly. There had been about a month of relative calm before Pyongyang test-fired an intermediate-range ballistic missile, which flew over Japan before crashing harmlessly into the ocean. The test, in our estimation, reflected either North Korea’s dissatisfaction with the status of the negotiations underway or Kim Jong Un’s belief that Washington would not, in fact, attack. We thought the former was the more likely interpretation. It now appears that talks have collapsed altogether.

Kim called Washington’s bluff. Now Washington has to decide how it will respond. At stake is nothing less than the regional balance of power for decades to come.

An Unusual Back and Forth

This isn’t as hyperbolic as it sounds. The standoff between Pyongyang and Washington doesn’t exist in a vacuum. It directly implicates China, Japan and South Korea, all of which have different ideas for how the crisis would ideally unfold. What the events of the weekend did, more than anything else, was lay bare the conflicting imperatives of the U.S. and South Korea in particular. U.S. President Donald Trump accused South Korea of “appeasement.” South Korean President Moon Jae-in responded by saying Seoul would not tolerate North Korean nuclear advances while adding, diplomatically, that it would not abandon the idea of peaceful resolution.

This isn’t the usual back and forth of politicians. Embedded in the statements are each country’s measure of the crisis. South Korea must, above all, preserve Seoul. It cannot allow another Korean War to break out. (The first one claimed the lives of more than a million South Koreans.) The U.S. must, above all, prevent North Korea from acquiring a nuclear weapon that could reach the United States – something that might be possible only by an attack. The U.S. cannot achieve its imperative by force without denying South Korea its imperative. After all, North Korea’s artillery is aimed at Seoul, not San Francisco.

(click to enlarge)

Our assessment dictates that U.S. interests outweigh South Korea – alliances aside, Washington would do right by itself by attacking North Korea, and South Korea would join the fray. Sure, South Korea could buy some time by exhausting diplomatic options, but ultimately it would do what the U.S. wanted it to. But what if we’re wrong? What if a U.S. attack is predicated on South Korean involvement? What if the U.S. can’t attack if Seoul doesn’t participate?

If this is the case, then the U.S. is simply going to have to accept North Korea as a nuclear power. North Korea, having ensured its survival and the gamble that threatening Seoul would give it enough time to develop a nuclear weapon, would then be able to do what it has long wanted: to unify the peninsula under its rule. This wouldn’t be done forcefully or quickly – Pyongyang would instead use its newfound security to pressure the South to abandon its defense treaty with the U.S. and to get U.S. troops off the peninsula. As far-fetched as it might seem, it is a viable scenario if Pyongyang possesses a nuclear deterrent.

And it is a scenario that would profoundly change the balance of power in East Asia. It would undermine the credibility of U.S. security guarantees, forcing countries such as Japan to reconsider the terms of their alliance. If Japan cannot depend on the U.S., then it would likely redevelop offensive military capabilities of its own (something it is already considering doing).

China would benefit from this scenario. Beijing, of course, would welcome any weakening of the U.S. position in Asia. The government could point to the frailty of U.S. promises as a way to enhance its position, especially among U.S. allies like Indonesia and the Philippines. It also wants U.S. troops to leave South Korea. Still, it is not without risks. A unified Korean Peninsula could threaten Chinese security by itself, and it could be a longer-term threat if, when unified, it falls under the control of Seoul.

The Unthinkable

The situation today, then, is similar to what it was in 1950, during the outbreak of the Korean War. Almost 70 years ago, the U.S. fought on the peninsula not because the land was geographically or strategically important but because it needed to assure its allies it would help them in their time of need. There are a couple of important differences, however. North Korea is pursuing a weapons program, not South Korean territory, and there is no equivalent to the Soviet Union. (China is powerful, but it is no Soviet Union.)

The U.N. Security Council held an emergency meeting after North Korea’s latest nuclear test. KENA BETANCUR/AFP/Getty Images

This means the crisis might play out differently than expected. Unlike the invasion of an ally, a nuclear program is not something the U.S. public can as easily demand a response for. That there is no Soviet Union means the stakes are somewhat lower, since there is no greater enemy waiting in the wings. Rather than go to war, Washington may decide to double down on its maritime strategy of dominating the Pacific and supporting, with the full force of American power, the allies it needs in order to do that. South Korea’s unwillingness to go to war gives credence to this theory.

For all its plausibility, this scenario is still a ways off. The U.S. still has reason to attack North Korea – preventing the emergence of a threat to the territorial United States and maintaining the balance of power in East Asia with Washington on top. If North Korea acquires a weapon, then the U.S. can achieve neither of these imperatives. The United States, therefore, may yet override South Korea’s interests.

(We should also consider the possibility that the U.S. was bluffing from the start, hoping to cow North Korea into submission. Now that the bluff has failed, the U.S. may be preparing for an attack as a matter of course. If so, we shouldn’t read too much into the time it took the U.S. to retaliate, if it retaliates, to the North Korean nuclear test.)

In geopolitics, forces such as economic needs and political survival compel the behavior of nations. Such forces explain why South Korea is dragging its feet and why, despite all the directions in which the U.S. is pulled, our model suggested war was the most likely outcome. But the events of the past few days have forced us to think of realities that were unthinkable a mere few weeks ago.

GPF Team
Geopolitical Futures is a company that charts the course of the international system. It’s an ambitious mission, maybe even foolhardy, but hear us out.