Atheism as a word just did not explain the danger and harm religion has inflicted on people. Positive or negative atheism as terms do not bring out the total rejection that religion should have anything to do with how society should be governed or considered a civic role to be involved in such a duty. That was why Hitchens used the term anti-theist.
Precisely because it is such a frequently used criticism of religious faith, the argument that war is a product of religion is worth considering. After all, we have recently had some horrific imagery from the Middle East that seems to suggest that religion is a bad thing. Nevertheless a number of points strike me.