In a recent game on a standard map with 5 civs remaining and I was about ten to fifteen turns from completing the Space Ship, I was in a nasty world war. China and Korea were against me, France was on my side, and Japan was neutral. My core/spaceship cities were near the Chinese border, so I wanted peace. I built a few nukes just before they opened up negotiations, and when the refused peace, I let them have it. The quickly made peace, as did Korea, now against the #1 and #3 civs(China was #2). Has anyone else tried to nuke other civs into a peace treaty?