Bush didn’t have the right and the Iraq war shouldn’t have happened. Saddam should have been removed from power in 91 at the end of Desert Storm (a colossal error that he wasn’t), but when he wasn’t the US didn’t have the right to unilaterally declare war and invade over made up WMDs a dozen years later.
However it is very clear that Saddam was a brutal dictator who ruled over his population through fear and atrocities committed against them. He attempted to wipe out the Iraqi Kurds, using chemical weapons, weapons he used multiple times which are war crimes. Ukraine is a democratic nation.
So there’s just a wee bit of a difference there, ya know.