He did it. Kim Jong Un defied the world, again. Despite the American warships, despite the Chinese pressure, North Korea’s leader tested another illicit missile. Even if the practice launch “fizzled,” as with gifts, it’s the thought that counts—and in this case, the thoughts are pretty disturbing. And he’s still got a nuke “all primed and ready” to test.

Of course, North Korea has conducted nuclear tests on five previous occasions, including twice last year (not to mention 24 provocative missile tests in the same twelve-month stretch)—and US aircraft carrier visits to the region are not rare. But the backdrop of palpably increased tensions against which these developments are taking place gives them a particularly ominous character.

While an outbreak of war remains unlikely, because this recent cycle continues a long, dangerous trend, we have to ask: What would a war to end the North Korean regime look like? What historical example could we reach to? It is critically important for planners to set their scales correctly to understand the scope war might entail. And in this case, the task’s enormity demands accurate forecasting.

Twenty years ago, an American commander in Korea estimated a war with North Korea would take a million lives and cost $1 trillion (and that was against a pre-nuclear North). More recently, about a year ago, the previous US commander in Korea, Gen. Curtis Scaparrotti, testified to the US Congress that, “Given the size of [North Korean] forces and the weaponry involved,” a war there would be “akin to the Korean War and World War II—very complex, probably high casualty.” Translating this most recent assessment from alpha to numeric puts us somewhere between 40,000 and 400,000 battle deaths. That’s a lot, but, it does get us to a historical precedent. Another major Pacific operation featured similarly high casualty estimates: Operation Downfall. This was the planned invasion to defeat the Empire of Japan at the end of the Second World War—and it never actually happened because the Japanese surrendered before it kicked off. Still, thinking through the similarities is a worthy activity in the face of such a high-stakes endeavor.

The planning for Operation Downfall had many features that would be similar to a conventional assault on North Korea. The first is that against Japan, the US objective was unconditional surrender to remove a distant, significant threat to US vital interests. Against North Korea, the US objective is verifiable, complete surrender of its nuclear program, another distant, significant threat to US vital interests. The geographies have remarkable similarities, if one considers the combination of the nearly impenetrable DMZ and non-accessibility of the North Korean-Chinese border for US military use—a fact that makes North Korea into a sort of manmade island (like Japan 1945), which drives US military options centered on long-haul power projection and amphibious approaches. Also, in 1945, US war planners’ first assumption was they would be “opposed not only by the available organized military forces of the Empire, but also by a fanatically hostile population.” Modern North Korea is similarly hostile; loyalty is strong and a not-insignificant number of civilians will fight hard. Lastly, the defender’s strike threats are actually fairly comparable—Japan had thousands of kamikaze planes and kaiten (suicide) boats which acted as human-guided deep-strike munitions, while today’s North Korea similarly has thousands of missiles and rockets, which are tech-led deep-strike munitions. And both foes used years to dig in and improve defensive positions ready for oncoming attackers. 1945’s Empire of Japan and 2017’s North Korea pose many similar military challenges.

But they’re not the same—so, what makes these two operations different? First, the most obvious is the nuclear genie is out of the bottle now, having been let out at Hiroshima and Nagasaki. Nobody has the ability to question or “un-know” that nuclear weapons are indiscriminate and devastating; because we have two mushroom-clouded data points, today’s planners understand the gravity of the situation better than they did in 1945. Second, another departure point is that we live in an unconstrained media age today, where just about anybody with a laptop can get in the news game. Oppositely, the Second World War was a relatively controlled era, in which governments had much more say in how and when stories broke. A case in point is that New York Times journalist William Laurence was essentially given (and handled in the release of) the story on the first atomic bomb. Modern technology makes everyone a reporter and broadcaster; yesterday’s Edward R. Murrow and Tom Brokaw regularly get scooped by today’s smartphone-wielding Jane and John Q. Public—and while this means broader coverage, it also means public panic has the potential to escalate rapidly. Third, we live in a relatively multipolar world compared to the end of World War II, when much of the world lay in ruin and the United States was in a much more dominant position. Lastly, the lethality of today’s weapons technology threatens high casualty figures in societies where nations have fewer children and seem relatively less willing to spend them at war. Another contrasting data point.

What does it all mean? Stepping back from these broad points of comparison between planning Japan’s “Downfall,” and an invasion of modern North Korea—what can we learn?

Here are some initial thoughts, from the hip, that seem like useful crossover points in thinking through such a serious undertaking. Several considerations come to mind, the first of which is to be prepared to change demands and make concessions during the endgame-bargaining stage with your opponent to achieve swifter strategic victory. For example, in Japan, the United States ultimately dropped the pursuit of an unconditional surrender in favor of allowing one condition (letting the Emperor remain), thereby avoiding a long, drawn-out fight to compel the surrender of millions of Imperial Japanese soldiers still left in the Japanese home islands and in China. Second, technology like nuclear weapons might provide a way to a cost-effective outcome, but there’s no such thing as a cost-free outcome—use of such a weapon still carried a price in that the world held the United States accountable for using a fundamentally indiscriminate weapon that killed many innocent civilians (even if most agreed with its military necessity). And, with respect to the broader issue of ethics, we must think utilitarian when considering options for situations like Japan 1945 or North Korea 2017, because no matter what, somebody’s getting hurt, it’s just a question of who and how (i.e., even doing nothing is a choice that allows continued destabilizing nuclear progress and leaves millions of North Korean citizens in de facto slavery). It is imperative we seek the best outcome that minimizes harm and maximizes benefit. Lastly, coalition assembly is required, for such an enormous operation in the Pacific makes it necessary to break beyond service and international and institutional challenges. When it’s this big, we cannot fail.

History tempts us by demonstrating that we occasionally don’t have to follow through on our planning for the hard ones (like Japan’s “Downfall”). It gets us thinking: Maybe Kim Jong Un won’t push the next button? Maybe the North Koreans will come to the table? Maybe the United States won’t have to attack North Korea?

Or, this time, we might just have to follow through. And so while it’s natural to desperately want to avoid it, it’s necessary to start thinking through a North Korean “Downfall.”


Maj. ML Cavanaugh is a US Army Strategist and a Non-Resident Fellow with the Modern War Institute at West Point, and looks forward to connecting via Twitter @MLCavanaugh.

The views expressed herein are those of the author and not necessarily those of West Point, the Department of the Army, the Department of Defense, or any agency of the US government.