He gives a religious blessing to murder:

Last night, on Fox News, Sean Hannity insisted that United States needs to "take out" Iranian President Mahmoud Ahmadinejad. Warren said he agreed. Hannity asked, "Am I advocating something dark, evil or something righteous?" Warren responded, "Well, actually, the Bible says that evil cannot be negotiated with. It has to just be stopped.... In fact, that is the legitimate role of government. The Bible says that God puts government on earth to punish evildoers. Not good-doers. Evildoers."

Some insist that Warren is a centrist, moderate type. He is, in fact, a very hard-core Christianist integrated firmly into the GOP. As such, he sees government as a divine institution authorized to punish evil and promote good - as fundamentalist Christians view those things.