Permissible and Obligatory
These are two categories of right action. Obligatory actions are a kind of permissible action. (If an action is obligatory, you can bet it's permissible.) The invasion is permissible for the allies to undertake, since it reduces the physical insecurity of those innocents affects; an action can't be wrong if it only helps innocents. I don't think the invasion is obligatory. We sacrifice too many of our men in undertaking it. This sacrifice outweighs the good it does for innocents. The reason is that the number of innocents under threat must be very, very high to make it obligatory for us to risk around 1,000 of our soldiers to help them. How high, I don't know, but you get the idea: much, much higher than 1,000. Millions. In other words, the invasion is a moral option. We may invade, or not. Whether it is prudentially rational for us to invade (as I think it is) is not relevant to the moral question of permissibility. It may be imprudent, even foolish not to invade and still permissible. (On the other hand, it may be obligatory for our government to invade if the government has a duty to protect us. But leave that aside. Consider the U.S. as a single person.)
The shame of Canada, then, is not that it fails its duty to aid Iraqi innocents. It's shame is that it argued against, and rejected, the permissibility of the invasion; it thus impeded the mission psychologically and distorted moral facts. It's shame is that it does nothing to support the invasion, in the way of moral, logistical or financial support. It's shame is that it is a security freeloader. It won't fight, but it will enjoy the security of reduction of terrorism. And as Aristotle would have put it, Canada's shame is that the invasion is an example of fine action; Canada backs down, in cowardice, hatred and envy, from an opportunity to engage in fine action with its friends. Canada has a duty to help the invasion in some way. Chretien was upbraided today in Parliament by a right-wing Alliance party member. He immediately justified his withholding support for the invasion on the following grounds: that Canada is a sovereign state that acts independently. This non sequitur is always the first reason Canadians give for maintaining their broken socialized health care system: difference from the U.S. This is shameful. Oddly, Canada had a duty to help the invasion where the U.S. perhaps did not have a duty to undertake it.
(Notice I don't speak of the shame of the French and Germans. They are shameless, and there is no point speaking about shame in their connection. They are morally dysfunctional societies.)
Some kinds of permissible action are supererogatory: beyond the call of duty: for the sake of others and requiring concession of one's own interests. The invasion of Iraq is not supererogatory, since it is in the U.S.'s interest to take out the Saddam regime. But since the invasion is not obligatory, the fact that similarly distressed peoples go without U.S. rescue is not an indication of U.S. hypocrisy. The U.S. has a right not to exercise its option to take out other murderous regimes. That it decides to exercise the option in the case of Iraq is therefore no grounds for the prevalent charge of hypocrisy heard today on the left. On the contrary, the fact that the U.S. clearly takes the rescue of Iraqis as one reason for invasion implies that it ought to be thanked by the rescued people, as I'm sure it already is and will be. One thanks a fireman who risks his life for one, even if he has additional, self-interested reasons for saving one.