"...there was an Al Qaeda terrorist base..."

Ansar al-Islam was a group with Al Queda links, based in a part of North East Iraq in between the Kurdish autonomous area and the Iranian border. This area had been completely outside the conmtrol of the regime in Baghdad for many years. And Ansar al-Islam was very hostile to Saddam (and vice versa).

Saddam's regime was a very nasty one. But not to be confused with Al Qaeda, or with those who had attacked the USA at any time. (Though efforts were made by the US government to confuse them at part of the run-up to the war.)