Today's pop quiz

Media Matters reports this exchange on CNN:

Discussing U.S. negotiations with Iran over its purported nuclear program, CNN senior national correspondent John Roberts commented that 'Iraq endured 11 years of sanctions, and, you know, we still had to go to war to get rid of what it was that they had.' . . . Blitzer responded: 'Good point, John.'

Here's the quiz:
1) What was it, exactly, that Iraq had?
2) Why did the United States "have to go to war" to get rid of it?
3) Why did neither Blitzer nor Roberts remember that Iraq actually didn't have any weapons?
4) And why did they think this had anything to do with Iran anyway?