I actually agree with you that Christian beliefs can also be harmful and counterproductive
Bush's irrational religious beliefs led him to reject the promising and valuable stem cell research for example.
But I really don't know how large a role his religious fervor played in launching the misadventure in Iraq, instead of staying focused on defeating Al Queda and other Islamic terrorists, in Afghanistan and elsewhere around the world. It strikes me more as simply the impulsive act of an incompetent cowboy who's angry and lashes out blindly at the big, visible target of Saddam.