Except for the tiny fact that you attack Germany, you attack EU. And that's pretty much a world war right there. Nobody wants another world war, don't be silly.

M.A.D. still exists by the way. It's still why all major nations are at peace and why the EU gave so much flak to the US a few years ago when Bush wanted to install a nuclear shield. He later had to back down or serious stuff would've happened. (afaik)

Also, according to wikipedia, Europe has 150 to 240 nuclear warheads. Plenty enough to destroy all US major cities.