J., a loyal MR reader, asked me for a post on “proliferation and separately nuclear exchange (war).”

Let’s try the latter. Every now and then I ask myself what is the most likely use of nuclear weapons, putting aside dirty bombs from terrorists and the like.

My first pick is a scenario where North Korea bombs a Japanese city, perhaps Hiroshima or Nagasaki. Imagine a North Korean regime in the throes of desperation, actually somewhat rational, and playing a mixed strategy with some probability of nuclear weapons use. Say the bluff is called and they feel a need to make a statement. I don’t think they would bomb their brethren in South Korea, nor would they opt for China, which could crush them like a bug. Japan, still perceived as a historic enemy by the way, is the obvious target. It’s close enough to reach, and they don’t have nuclear weapons of their own. Tokyo however must be held in reserve as a target, so Hiroshima or Nagasaki it would be. “Just big enough to send a message” — sound familiar?

My second pick is a scenario where the United States and China are fighting a naval battle in the South China Sea, or perhaps further north, as part of a limited exchange, not a full war. The United States is about to win the battle, and the Chinese leadership fears a military or other Party-based coup in response. So they use nuclear weapons, perhaps tactical nukes, to turn the tide in the battle and save their skins. They figure the U.S. won’t respond with a full-blown nuclear war. (America, if it lost a comparable naval battle, is more likely to just turn tail and run, at least in the short run.)

Fortunately, the chances of either of these events are quite low. Unfortunately, the chances are also rising somewhat.

There is more noise as of late coming from the India vs. Pakistan side (Pakistan threatening to use nukes to respond to a ground invasion, plus Pakistan having a nuclear submarine), but I don’t see actual evidence that the chance of nuclear war there has gone up. It has to make the list, but it’s not one of my top two scenarios.

My core model, by the way, is that political leaders are rational in the loose sense. So if you are looking for instances of possible nuclear weapons use, consider cases where politicians might be facing relatively dramatic “career-ending” events if they lose a smaller-level struggle.