A major hurricane, a nuclear accident and a nuclear detonation -- all simulated, and all occurring in Texas -- are among the challenges facing U.S. Northern Command forces during exercise Unified Defense '04. Simulated events also include aircraft hijackings, threats from a fictitious country testing its strategic capabilities, and attacks on maritime and port security by domestic terrorists in Alaska. Though the attacks are all simulated, the responses are "real-world," said Army Lt. Col. Tim Croft, a NORTHCOM exercise planner. He said some 50 different local, state and federal agencies in Texas, Alaska, Virginia, Colorado, and Washington, D.C., are participating...