What you're doing is arguing based on subtley false premises. This is sophistry.
You're saying that since US bombs sometimes kill civilians, we have no authority to say a guy like Saddam is irrational because he likes to use his weapons on civilians. The false conclusion : since in the end both sides kill civilians, one shouldn't be judging the other.
This is akin to saying "well, we can't really pass judgement on your tumor sir. There are trillions of healthy living cells around the the area. No matter how precise my scalpel is, blood will be spilled and innocent cells will die needlessly. Thus ignoring the unfortunate fact that the rest of the body will have to deal with this inaction later when the cancer decides it's had enough sitting in one place.
But of course this is extremely wrong. Saddam has no compunctions about intentionally using weapons against civilians to accomplish his goals (read : Kurds). The US uses its weapons against military targets _only_. You will never find a case where the US said "let's blow up civilians". To draw a comparison between them is completely misguided. You're forgetting that when the US does cause the deaths of civilians it is _always_ while engaged in lawful military activities against an armed opponent - very likely this said fellow has been marked as an opponent because he decided he was going to start killing civilians on his own. Blowing up school buses, gassing Kurds, flying planes into buildings are all 100% different because they _intentionally_ target the innocent.
You may argue that it doesn't matter what the morals are - if the US attacks, many civilians will be dead regardless. This is true, but it ignores two key points :
- All steps will be taken to minimize these casualties. Reparations in the tens of billions have and will continue to be paid for mistakes. The US is the _only_ country that has such a policy.
- By _not_ acting, we put 10 times as many lives in just as much peril in the future.
But I've seen this argument fought 10,000x. I have no desire to go any further.