Religious fanatics. Twenty years ago, this wasn't the case.

The communist states collapsed in a domino effect (except Cuba and North Korea) in 1989-1991. Except for Romania, it was a peaceful revolution.

I must have missed the collapse of China.

You might want to remember why the communist states collapsed. At tremendous cost, the United States and its allies held off the Soviet empire for decades. And those who supported a strong United States, like Ronald Reagan and others, took endless crap for it the whole time. Although they don't own up to it now, the Left in this country called for unilateral nuclear disarmament for years.

You might also want to remember that the "peaceful revolution" was after tens of millions of deaths in those nations.

At least you can see that deterrence has little effect on fanatics.