It was viewed as illegitimate inside the US too.
You’re recollection of events is clearly skewed. Something like 80% of the population approved of it at first. Meanwhile there were protests in the millions of people around the world against it.
https://en.wikipedia.org/wiki/Public_opinion_in_the_United_States_on_the_invasion_of_Iraq
A Gallup poll made on behalf of CNN and USA Today concluded that 79% of Americans thought the Iraq War was justified, with or without conclusive evidence of illegal weapons.
Mind you you also support apartheid by buying an overpriced product made in occupied West Bank Territories.
Settlersdream