It's important to get this right: I don't 'defend' the Iranian leadership. I support the Iranian left and its working class. I do, however, think that efforts to be clear about the sources and extent of its obvious shortcomings are valuable. The Islamic Republic is "a vile dictatorship", the Bollinger neocons* will scream, and in reply, we should that that it is not a dictatorship, but that it is highly authoritarian; they will say that the source of Iran's tyranny is Islam, and we should reply that its source is in fact a class bloc that consolidated power and defeated the Left shortly after the revolution (and that the last thing the neocons wanted was for the Left to succeed in that struggle); they will say that Iran is plotting the murder of the Jews, repressing women, (and they might even get round to mentioning what some refer to as an anti-gay purge), and our response should be to clearly separate fact from fiction, for example allowing that women are repressed but also that they have fought for and won some unique victories etc. This is what I mean by a propaganda struggle. It isn't designed to effect US policy, which alone it can't. It is designed to neutralise the propaganda raised in its defense: the main effect of propaganda is to confuse and frighten people, and by clarifying and unfrightening people, we stand a better chance of effectively mobilising antiwar sentiment.
*cf Champagne socialists