"Only parties with roughly equal powers can enter into an alliance. Washington's demand is not that Tehran be its ally, which is why it rejected the overtures from Tehran during the Khatami era."
But my point was that the Iranian elite would ally themselves to the US if they could, not that the US wanted it. I wanted to make the point that they have no intrinsically progressive dynamic.
Also I agree with you when you say to Doug that 'leftist' in this context is not necessarily good (after all the 'leftists' in the Irish republican movement, the 'Officials' were those that favoured collaboration with British imperialism). It is just that the pro-western outlook of the Iranian leftists (descendants of Tudeh) does not necessarily imply that the current regime's populism is preferable.
As for killing leftists, I think most would agree that executing your political opponents should demand a high threshold of justification, which the Iranian regime has not met.