What to do if nukes are incoming?
God's Will be done. He knows what he is doing, and so if a bomb fell tomorrow, I'd thank God for creating me and dying for me and I'd glorify Him. If the fallout made me die an agonizing death, it would be my purgatory here on Earth.
Suffering here, even if for years, is like one second compared to eternity, and Death is just a transition to real life.