Militant atheism leads to communism.
Actually, that's not true at all. As a general rule, "atheism" (or even "militant atheism") leads to no particular political philosophy.
It's true that atheism is often a facet of "Communist" states, but more often than not, it's not "atheism" but anti-theism -- as a counterpoint to an potential challenges to the cults of personality that are so often elemental to dictatorships (indeed, even Stalin had churches and religion in his Soviet Union).
Even Marx, the ideological 'founding father' of Communism, stated that atheism (in his words, an affirmation of man's existence, contrary to the false comfort of religion) is irrelevant in a truly communist state.
But, again, "atheism" is simply a lack of belief. It has nothing to do with one's political leanings or affiliations.