Atheism was responsible for over 100 million deaths in the 20th century alone, and that's on the backs of just four men (Stalin, Pol Pot, Mao, Hitler).
Err... Hitler? An atheist? It must be some other Hitler, 'cause Adolf was a hardcore Christian. Secondly, Atheism is a not lack of belief altogether, but a lack of belief in a god or "the God". Which means that a lack of belief in God is the only thing that is common amongst Atheists worldwide, and the individual beliefs of Atheists can be more different from each other than the beliefs of Christians and Buddhists or Muslims and Hindus. Every Atheist strives to define his/her own standards of morality and good behavior based on their circumstances, rather then blindly following a predefined and rigid code of ethics concocted by uneducated tribesmen from thousands of years ago. As for Stalin, Pol Pot and Mao; well, the reason these people abolished religion was to have absolute, unshared authority over the public, and not because they wanted evolution to be taught in public schools, or they cared about the abortion issue.
Imagine if every country in the world was run by atheists? Humanity would self-destruct in a matter of a few short years.
You fool, (almost) every country is already being run (or rather, being kept running) by atheists, even the bloody theocracies, and that is how it has been for a LONG time. Once you get to that level of power and gain access to higher levels of information, the true nature of religion, as just another method of control, as just another leash, becomes transparent, and the claim of adherence to the most popular local religion becomes a prudent political policy.
...continued (Your comment is long enough to count as spam, shorten it. >:( screw you)