> And why do we assume that the tech is sufficiently advanced to e.g. take out every major city at the push of a button? I guess you didn't grow up under the c

> And why do we assume that the tech is sufficiently advanced to e.g. take out every major city at the push of a button? I guess you didn't grow up under the cold war? Typical nuclear weapons are 10-20 megatons of explosive force and can destroy everything within a city-wide radius or more. There is the capability to deliver 100-200 megaton mega weapons too (they have been tested in the 60's, look up Tsar Bomba). Delivery devices like ICBMs include dozens of these warheads in independently target-able munitions--the idea is that one big missile can be shot down, but a shower of dozens and dozens of warheads is impossible to stop when only one needs to hit. These missiles can launch from undetectable nuclear-powered submarines laying in wait anywhere on 70% of the globe (even under a sheet of arctic ice). As far as numbers go they were vastly reduced in the 90s, but both the US and Russia have enough nuclear munitions left to destroy every major city in the world.