I note that the plotters were a gang of wannabes that didn't know what to do. So they called Baghdad, and two experts showed up on their doorstep to show them what to do.
The two Iraqi agents led the attack, left the country, and left the wannabes to take the fall.
That Yasin is a Iraqi agent isn't in doubt. Since Yousef was sent from Iraq to help him, thats pretty clear too. Although he is sometimes thought to be Baluchi, I always note that his co-conspirators called him "the Iraqi". I figure native arabic speakers would recognize an Iraqi accent, versus the accent of someone who spoke it as a second language.
In essence, Saddam is the author of the first attack on the World Trade Center. We now know that there were meetings between Saddam's intel people and the 911 attackers as well, and we have reports that he planned a big false flag attack on the US. 911 was that "false flag" attack, its pretty plain to me. 911 was Saddam's plot to finish what he started in 1993.