You need to go back and look at the history of that visit. Thats back when Iraq and Iran were at war. The US and the Un supported Iraq during this war. This was not that long after the Iran hostage crisis, so you can understand why we would support Iraq. This was also during the cold war and Russia was supporting Iran.
Rumsfeld was also sent there by the President, unlike Polosi who has no right spouting forghein policy of the US.