For New Jerseyans, it was perhaps the most chilling image evoked since the Twin Towers fell: An al Qaeda operative sitting patiently in a Newark coffee shop, eyeing the exits and entrances at the nearby Prudential tower, studying security shifts and employee traffic, and sketching out a plan to bomb the city's skyline jewel and kill thousands of people. Yesterday, a British national said it was all true. Dhiran Barot, 32, pleaded guilty in London to conspiracy to murder, admitting that he plotted with others in 2000 and 2001 to attack high-profile targets in Great Britain, New York, Washington, D.C.,...