Was it justified?
The justification most people use is that Iraq was believed (without actual evidence) of having nuclear weapons, and the fact the government was run by an evil dictator.
However, there were no nuclear weapons and nor had they the capability to launch them at the US. The war brought Al-Qaeda into the country and created a civil war between the the two main religions (granted, that was more or less unpredictable).
Still, you can't go to war over a baseless threat. There simply was no evidence Iraq had any nuclear weapons other than Saddam Hussein's threats.
And of course evil dictators must always be brought down, but not by a full blown war. There are many other countries standing right now that have evil dictators, but you solve the issue through revolutions like the Arab Spring. If the people want it, then help them, but you can't force it onto them.
What's your opinion on the Iraq War?
EDIT: I forgot to mention that this war paid on credit - one of the most unintelligent decisions ever made in US history since Hoover's inaction during the Great Depression.
1) Sapphire sucks
2) You're on a website filled with a bunch of angst filled teens who don't have the first idea about politics or war, what kind of answers do you expect?