...in the end, and deep down... all extremists are about the Group. - of course.
I disagree with Hitchens, here.
Mao, Stalin and others weren't acting on some kind of religious impulse, IMO.
Atheism is simply a lack of belief in God. That's it. It's not a set of values for societies to live by or for governments to implement.
Mao massacred 60 million of his own citizens neither in the name of religion nor in the name of atheism. He massacred those people in the name of his political ideology.
We should blame religion when religious regimes kill people in the name of their religion.
We can't blame religion when secular regimes kill people. This is what Hitchens appears to be doing and I disagree with him.
Of course, we also can't blame atheism when secular regimes kill people, either.