not even the most militant political vision can justify the wanton killing of civilians simply for the sake of spectacle and show of power. Most moral ideas almost anywhere, religious or non-religious, can be pushed to levels of blind fanaticism that discredit the original moral concept. Islam, Christianity, Judaism, Buddhism, yes, all do it.
And take socialism — the vision of an economically just society. In the Soviet Union under Stalin and in China under Mao abstract socialist principles ended up justifying the deaths of more than 40 million people