Christians: the Crusades, back 700 years ago, and the Troubles in Northern Ireland.
Muslims: Modern islamofascism and terrorism.
Yet, as right-wing as these religions can be, a liberal interpretation would slide us down the slippery slope of some kind of theo-communist state. Being an agnostic myself, I have a fairly impartial view.
Mmm... they're still doing it, period. Instead of directly killing people, they lobby the government to begin wars in the Middle East. If we didn't have such a strong, intolerant religious right in America, the Iraq war would never have happened.
All religions lobby all governments. I'm not denying that the Christian right is indeed intolerant, but the Iraq War was influenced by other factors than them - Bush, for example, and Tony Blair. Not to mention the Kurdish genocide way back, which still resonates today. No WMDs have been found, but I think Bush and Blair were more disillusioned than any way controlled by the religious right.