Ammar al-Baluchi, once considered a bit player, is alleged to have served as trainer and banker for several of the hijackers. Until recently, Ammar al-Baluchi was considered a peripheral player in Al Qaeda, a functionary who made travel arrangements and wired money for terrorists. But new government disclosures place Baluchi in a larger role in the Sept. 11 preparations and rank him No. 4 among the conspirators captured by U.S. forces after the 2001 terrorist attacks. Indeed, investigators say he was instrumental in acquiring a Boeing 747 flight simulator and a Boeing 767 flight-deck video for the hijackers to practice...