Left and right have different flavors of true-belief. On the left it's a political flavor, on the right it's a religious flavor. I think if you compare the political true-belief of the left with the political true-belief of the right it looks more balanced. The left has far fewer religious nutjobs. (I cannot say that the right has fewer political nutjobs.) People inclined to be nutty about things will find their own things to be nutty about. Church and state are roughly equal opportunities for nuttiness. The left only looks nuttier from the libertarian view because of the belief that it's okay for the agents of government to do things that it is not okay for the agents of god to do. This makes religion less harmful in that regard but doesn't make it less of a true-believer thing. It's much more true-believer than the statist left. Warmongering is a very right-wing attitude not nearly as pervasive on the left, and that's as true-believer as anything on the left, just of a different flavor, going by the standards he mentions where not being imposing makes it less true-believerish.