Why expect Iran to cooperate when others do not?

I just finished reading an article in the Economist:
http://www.economist.com/world/mideast-africa/displayStory.cfm?story_id=12957301

The article is about whether or not Israeli shelling of civilian targets constitutes a war crime. The problem as the article states is with the difficulty of defining war crimes where sophisticated technology is involved: "But international law has found it easier to deal with low-tech mass killings at close quarters, as in the Rwandan genocide of 1994, than with the rights and wrongs of Western-style air campaigns. Civilians are repeatedly hit by NATO aircraft in Afghanistan, but there are only regrets, not court-martials." I would also add that genocide as a war crime is a particularly tricky issue, as seen with the case of Darfur recently. The law as formulated by the UN is geared more at internal genocide than an external one; the law was meant to allow intervention in nations where otherwise national sovereignty had to be respected.

But as fascinating as this is, I'd like to highlight another portion of the article: "Isreal...tends to be wary of outside investigation. It declined to co-operate, for instance, with a UN inquiry into a shelling incident that killed 19 civilians in Gaza in 2006." I am not particularly surprised by this in many ways, partly because of the limitation imposed by the Israeli government on the media, especially the lack of access to Gaza. Nonetheless, the non-co-operation of Israel emphasizes the hypocritical stance of Western nations towards Israeli actions when compared with those of, for instance, Iran. For example: the repeated complaints about Iran's non-co-operation with the UN as per weapons inspections. Now I don't think that the Iranian government is in any way doing the right thing but this manner of double standards is very dangerous and counter-productive in assuring Middle-Eastern/Muslim nations that any peace process will be fair and balanced. Quite frankly, it seems ludicrous to expect this. Moreover, why should we expect Muslim nations to come to the table when they are being examined far more critically than others? There have been protests all over the world about Israeli actions in Gaza but there has been little action taken to stop the shelling and even less official/governmental criticism of Israeli actions (the UNHCR and the IRC notwithstanding; both are non-legislative organizations) which cannot be blindly judged to have been entirely aboveboard. Let the international watchdogs in please.