Here's something to think about when you go to bed
Most of the asteroids detonated, for that *is* what they did, in the upper atmosphere over an ocean.
Think of idiots on the ground, fingers near buttons, fear guiding their movements. Figure Russia and the US over the Ukraine, figure India and Pakistan, figure any of the usual nonsense that gets nations tense.
Now, think of one of those asteroids popping off over Washington, D.C., Moscow, London, pick anywhere in India or Pakistan when tensions are high at a level between Chelyabinsk and Tunguska.
A few years back, Pakistan and India *had* mobilized nuclear forces due to tensions between the two nations. Along came an asteroid that blew and set off these detectors globally.
Thankfully, it blew apart over the Med, with chunks landing largely around Libya.
That gave some pause and the nuclear forces of both sides stood down, for it'd have been only a short time later that that asteroid could've blown over their heads and a premature decision to launch could have triggered irretrievable actions.
As one who grew up during the Cold War, served in the military under Reagan, actually watched a real nuclear countdown be initiated and thankfully cancelled after the realization that things weren't at a war footing, but something else happened, I know how quickly things can go unimaginably wrong.
Something that occasionally does wake me up at night remembering programming flowing into a missile that was within seconds of launch.
But, nobody is watching for these. One launch on warn is all we'd need to join the dodo.