Prager's arguing that religious America hasn't been more violent or dangerous than Europe was in its most secular of centuries.
Cohen made the assertion that American-style religion was more dangerous than European-style secularism, and so far as I can tell, Prager proved him wrong -- Stalin and Hitler arose in Europe, not in America.
If he goes further and says that secularism as such and in itself has been more dangerous than religion, that's debateable, but he also shows Cohen's trick of defining communism and fascism and nazism as "religions" for the sham that it is.
But Prager may go wrong elsewhere: today's Western Europe is an exhausted society.
Arguably a vital, active society may be more dangerous than one that's become tired out and lost the will to assert its values.
Of course, the problem with that is that weak societies may be dangerous precisely in their weakness and inability to defend themselves.
That is very true and I agree that a religious America has not been the threat to the world that the Communists and the Nazis were. Not even close (despite what Nancy Pelosi believes.)
So Prager is correct in that simple comparison. But look again at what he says:
Secular fervor, i.e., communism and Nazism, slaughtered, tortured and enslaved more people in 50 years than all Europe's religious wars did in the course of centuries.
That is way to broad a generalization.
He is equating being nonreligious (i.e. secular) to Communism and Nazism. That is simply not true and by defining these aggressive socialist dictatorships by the single parameter of their nonreligious or even anti-religious foundations is way too much of an oversimplification for me. The world just doesn't revolve around whether you are religious or not. There are other things and Prager dismisses them all.
Now that doesn't make Cohen right either but I'm picking on Prager not Cohen.