We invaded Iraq on the pretense that they were getting yellowcake from Nigerian suppliers, and US suppliers were in Nigeria trying to sell yellowcake to Saddam Hussein. He wasn't interested.
We knew he wasn't interested because Joseph Wilson, a US diplomat, was involved in the efforts to make the sale. Hussein saw which way the wind was blowing.
When George W. Bush started talking about invading Iraq (in speeches blending vitriol against Hussein and anger over 9/11) Wilson published a report about how Hussein totally wasn't buying Yellowcake, which he knew about. And in response, the Bush administration burned Valerie Plame, who was Wilson's wife and an actual CIA operative who was active and abroad.
She made it home safely, and could no longer work as a CIA operative. In the cold war, burning a spy for political reasons showed CIA you were careless, and deserved to receive a tape of ten hours of your loved one screaming as she was tortured to death. But those were different times, and presidents then had a few more scruples (and knew not to do that).
According to Al Franken, about 75% of ground troops during the Iraq war believed they were there as revenge for the 9/11 attacks, even though Hussein and Iraq had nothing to do with the 9/11 attacks. A friend of mine in Virginia noted his teen daughter was taught in American History we were provoked to go into Iraq because of the 9/11 attacks and the International War on Terror. I was around in 2003 watching Republicans nation wide saying torture is AOK and waterboarding isn't really torture (until they went to have a SERE guy waterboard them for size. They all thought it was pretty terrible and even maybe torturous). Still, it was pretty clear that the IWoT and Iraq were separate things, even though the White House liked to conflate the two in speeches. Hussein and Al-Qaeda did not get along.
I remember the US attacked Iraq because Hussein allegedly had WMDs. The US couldn't find any. The US had strong intel beforehand there were no WMDs in Iraq and that Iraq was still recovering from the 1990-1991 gulf war.
I think George W. Bush and Dick Cheney just wanted to kill and torture some Arabs for being too brown and because they couldn't kill Saudis (like Osama Bin Laden, who figured largely in planning the 9/11 attacks). All the WMD nonsense was a deliberate lie.
