The world isn't as simple as good guys vs. bad guys. It's all shades of grey, and your ally on one issue might be your adversary on another issue.
His support for the Iran war could be that he genuinely believes it, as Iran is opposed to western hegemony and thus is a threat to western banks
He's said why from the very beginning. Iran having nuclear weapons would be bad for everyone. He's suggested people read the IAEA reports on Iran. Have you? There's no need to speculate on what his intentions are, you just need to do some reading.