The suddenly threatening possibility of nuclear war has a lot of people anxious this week, but Americans might not have as much to worry about as they think. If the United States dropped a bomb on North Korea, the conflict probably wouldn't last long — thanks to the destructive nature of nuclear bombs, there's only so long this chess game could last. However, the real questions come after the explosion, and those potential geopolitical conflicts need a lot more transparent solutions before anyone should feel justified in throwing the nuclear football.
If the United States really is going to bomb North Korea soon, it's very likely that the Trump administration would use its most serious firepower. It seems pretty pointless to leave any room for retaliation and risk the possibility of North Koreans launching more missiles, so the United States would probably just want one-and-done in this case. Plus, now that Donald Trump has talked a big game about "fire and fury like the world has never seen," it's extremely unlikely that he would back down if the situation escalates to the point of bombings.
The NUKEMAP, created by nuclear historian Alex Wellerstein, gives us a handy way to calculate what that single explosion might look like. According to Wellerstein, the largest bomb currently in the United States' arsenal has a payload equivalent to 1.2 megatons of dynamite — were it to drop directly over the center of Pyongyang, the explosion and resulting nuclear fallout would wipe out most of the country. Wellerstein's simulation predicts over 1 million fatalities and nearly another million injuries, with the radiation plume stretching almost all the way to China.
After that, it's unclear what action the United States would take. Trump has been heavily critical of giving aid to foreign countries, and it's entirely possible that he could leave someone else to clean up the mess.
With the North Korean government hypothetically obliterated, South Korea could step up to unify the peninsula again, or China could muscle its way in and take over the territory. Either way, it would mean billions of dollars and years of cleanup, so it's not really an enviable position. However, the world community would still have to keep a very close eye to ensure that terrorism or authoritarianism doesn't surge to fill the resulting power vacuum.
This scenario is still probably a long way from coming to fruition, but it does bring up some serious problems that would face the nation if it does come true. As far as the American people know, there's no plan for how to take responsibility for this action if bombing is deemed necessary. World leaders need to come together and figure out a plan before it's too late, because without an internationally coordinated strategy, history may repeat itself very quickly.