Is Buddhism the most peaceful religion?

As far as I know the only government who actually adhered to the principles of buddhism was that of the Indian ruler Asoka. Even under the early dali lamas Tibet was an aggressive expansive state. Burma, vietnam and cambodia were aggressive empire building states. Burma today is a despotic military autocracy, its leaders are nominally buddhist, but still persecute non buddhist minorities. Sri Lanka is embroiled in a bloody civil war against its hindu and muslim minorities. The ideology may be peaceful, but when it comes down to it buddhists are still people and act like every other person: imperfectly.