What’s the Big Deal About These US-South Korea Military Exercises?

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What’s the Big Deal About These US-South Korea Military Exercises?

A closer look at the costs and benefits of the annual Foal Eagle-Key Resolve exercises.

What’s the Big Deal About These US-South Korea Military Exercises?
Credit: U.S. Army/ Flickr

South Korea and the United States stage large-scale military exercises every March. Tens of thousands of U.S. troops and hundreds of thousands of their Korean counterparts participate. The exercises are gargantuan, costly, and they temporarily escalate tensions on an already volatile peninsula. They are also operationally necessary, and they further the United States’ strategic goals in the region despite the drawbacks I just mentioned. Long-term U.S. strategy for East Asia requires that South Korea eventually take “operational control” of its own security during any future Korean War. Unfortunately, the South Korean military is still not ready for this responsibility; these annual exercises are substantial steps towards that readiness.

More Power, More Problems

The United States could decisively defeat the Democratic People’s Republic of Korea in a military conflict. This is not really in dispute amongst military analysts. However, it behooves the United States to structure its forward deployed forces and foreign alliances such that it has to spend as little resources as possible on securing this goal. The highest priority interest on the peninsula is preventing a nuclear war and deterring the DPRK from attempting to forcefully reunify Korea. Currently, this requires a substantial U.S. military presence in South Korea and Japan — but, of course, the less effort the United States needs to expend to secure its strategic interests, the better. The annual ROK-U.S. military exercises make South Korea a stronger ally and increase both militaries’ ability to succeed together at lower cost, with less risk.

Though North Korea’s military could not defeat those of the United States or its allies, it could cause enormous damage to South Korea and Japan before it was destroyed. Sure, most of their tanks, submarines, and fighter aircraft are limping towards obsolescence, and their “air defense systems” deserve the quotation marks I just gave them. But their ballistic missile arsenal is frustratingly survivable, they enjoy significant geographical advantages over their potential adversaries, and they could — with ever-increasing reliability — strike East Asian targets with nuclear weapons. With thousands of live artillery constantly pointed at Seoul and ballistic missiles aimed at Tokyo, the first 60 minutes of any war would likely be catastrophic for our allies. Predicted civilian casualties usually number in the hundreds of thousands or millions. The sweet certainty of eventual victory turns rather bitter if it comes at the cost of Tokyo and Seoul.

A true victory on the Korean peninsula would require the rapid destruction of North Korean artillery, rocket, and ballistic missile assets (definitely including those related to nuclear warfare). Most preferably, this would coincide with the elimination of top DPRK military commanders. (The DPRK military’s command structure is highly centralized, so the fighting force writ-large is expected to crumble if beheaded.) To achieve a reliable capability in this regard, the United States and South Korea need to practice. A lot. Preferably every year. March sounds good.

Diplomatic Consequences

The annual Foal Eagle-Key Resolve exercises substantially heighten allied military capabilities, and it is this context in which they are of the greatest value. However, there are also wide-ranging diplomatic ramifications, some more favorable than others. Every March, the ties binding South Korea and the United States knit ever tighter as both countries demonstrate shared goals and the importance of their alliance. This can lead to tangible policy victories for the United States, as it did this month when the ROK and the US deployed the long-anticipated THAAD defense system on South Korean soil. Japan, arguably the United States’ closest regional ally — and unarguably its most powerful — also benefits from these annual exercises; Tokyo is safer when Seoul is stronger.

Some regional actors are predictably and pointedly displeased with the annual March exercises, and they are not shy about conveying their disapproval. The Chinese Foreign Ministry no doubt has a formulaic draft of condemnation saved in a folder, changing the relevant dates and names every year. Lately, as in several other contexts, China has added language demonstrating its thinning patience with North Korean behavior, criticizing their nuclear tests and violations of UN Security Council resolutions. China views the exercises as escalatory and unnecessarily provocative, a saber-rattling maneuver that increases the risk of a war that nobody really wants. China’s view isn’t incorrect — the exercises are escalatory, and they do temporarily increase the risk of conflict. For China, this downside is the most important byproduct of the exercises, the most significant effect on their interests. For the United States, it is a consciously accepted cost, one that does not outweigh the strategic benefits.

Risk of War

These war games do certainly increase the risk of a military confrontation, albeit temporarily, as the risk is only tangibly heightened while the exercises are ongoing. Still, accidents happen, and if a live round lands in (or simply too near) one party’s territory, actual war could be moments away. North Korea has taken to conducting ballistic missile tests concurrently with the U.S.-ROK exercises. If the United States or Japan deem any of these missiles a threat to their territory (or assets), they have vowed to shoot it down. Either side could use that interaction as casus belli — though, notably and perhaps predictably, the North’s case would be shakier and less accepted by the international community. Additionally, North Korea’s only hope of victory lies with an enormously successful first-strike. This, coupled with Pyongyang’s very real fear that these exercises might one day be merely a disguise for an actual invasion, makes a North Korean attack more likely every time the United States and South Korean forces suit up for war games.

I am reminded of a John Stewart segment from May 2015. Stewart plays back-to-back clips of news anchors proclaiming each year from 2006-2015 as the “worst allergy season yet,” with the “highest pollen count ever.” Yet, as he notes, they were correct: each successive year was the worst yet, with higher pollen counts than any previous recorded year. In much the same vein, many political-military analysts claim every March that the world is closer to another Korean War than it has ever been — they, too, are probably correct. The past year has seen a brazen political assassination using a WMD in a crowded international airport, a slew of nuclear and missile tests, and more executions of top DPRK officials as Kim Jong-Un tries to tighten his increasingly slippery grip on power. The last round of missile tests landed in Japan’s Economic Exclusive Zone, and if past behavior is any indication, March still has another round of North Korean missile tests left in it.

Should the United States increase its chances of winning a war when doing so would heighten the risk of fighting one? It’s the question at the heart of the security dilemma. In this case, resoundingly, yes. Capability lies at the heart of successful deterrence, and these exercises strengthen both. Furthermore, the Foal Eagle-Key Resolve exercises slowly but steadily shift the burden of deterrence from the United States onto the Republic of Korea while helping the ROK become more capable of bearing that same burden. This, in turn, frees up some resources that might be better spent elsewhere. Perhaps, for example, preventing the emergence of a regional hegemon or securing multi-trillion dollar trade routes.


The more the Republic of Korea is capable of securing itself, the less burden the United States will have to bear for Seoul’s security. The United States should definitely maintain forward deployment in South Korea for as long as deterrence against North Korea requires it — a dynamic unlikely to change in the near or medium-term future. (It would also likely be prudent to maintain some military presence in the peninsula even after reunification to balance against China, but that conversation warrants its own article.) The less the United States has to spend — in terms of strategic opportunity cost and military asset devotion — on securing the Korean peninsula, the more it can allocate to other top-tier strategic interests: preventing a regional hegemon; securing vital trade routes and sea lines of communication; and preserving military freedom of navigation throughout the Asia-Pacific.

Damen Cook is lead researcher at Strategic Sentinel.