The nation’s former deputy counterterrorism czar said yesterday that Al Qaeda operatives trained in Afghanistan came through Boston Harbor on liquid natural gas tankers from Algeria and that officials considered Boston a “logistical hub” for the terror network’s activities in New England before the attacks of Sept. 11, 2001. Roger Cressey, who was the top aide to former counterterrorism chief Richard A. Clarke, said “more than a dozen” stowaways with Al Qaeda ties had entered the United States in the late 1990s on tankers that made deliveries to the LNG terminal in Everett. Full Story