1] Any aggression outside his borders against a country aligned with US business interests will meet with harsh consequences. It can even be suicidal!
2] Any other aggressive use of force other than those specified above will be allowed to continue with impunity - the US has even aided in aggression directed against countries or groups hostile to the US business interests.
3] The US has never taken military action - or organized economic sanctions - against any country openly in possession of weaponry of mass destruction. That includes the despotic regimes of the old Soviet Union and present day China.
Since Saddam can't determine US economic interests and Iraq is right in the middle of oil country he has every incentive to keep the US from dictating political and economic policy to his country. Since he can't use any weapons of mass destruction without a huge risk of dire consequences, the claim that Saddam will reign destruction on his neighborhood is idiotic - at best! Why does the US government do its best chicken little imitation at the prospect of Saddam gaining weapons of mass destruction? What can or will he do - other than start acting like a grown up responsible leader - when he has the weapons to threaten others? Is having an overgrown adolescent like Clinton or a hyperactive chemically unbalanced Bush or a senile Reagan with a finger on the button any less dangerous? Our specious claims to moral superiority are soundly repudiated by our past.