Let's say you have a nice deep shelter where you do not have to worry about the actual explosions. You still have to live there long enough for things to cool down.
All the poor saps alive on the surface might not have a long life expectancy but they could summon up the energy to take revenge on the people who did this to them, if they were sure who it was, exactly.
Now they have these nice air vents and water supplies that work their way down to the shelter. If you thought one of these bad people were down there, you would figure out a way to disrupt it or poison it or whatever just as long as you could kill the bastards.
So, they work behind the scenes to manipulate events for maximum damage. They fund terrorists to cause strife among nations and do it in a way that they will eventually trace it back to us. If they do not have good enough weapons to attack us, they will provide them with the necessary ones.