On August 2 the destroyer USS Maddox was attacked by North Vietnamese torpedo boats while on electronic surveillance patrol in the Gulf of Tonkin.
The United States, for its part, has Special Forces, Army Rangers and Marines to monitor thousands of square miles at the Mexican border with night patrols, electronic sensors, pilotless drone aircraft first used 18 months ago in Afghanistan and helicopters with infrared scopes.
Analysts working at computer terminals in 12-hour shifts, round-the-clock, seven days a week, update computer databases with the latest information from Iraqi informants, Army patrols, electronic intercepts and other sources.
uses the plane for maritime patrol, electronic warfare, airborne warning and control, and reconnaissance work.
But they said some of the airports would introduce new, 24-hour security patrols and electronic surveillance of the flight paths used for takeoffs and landings.
Senior army officers explain that the physical structure itself will be reinforced by an elaborate system of electronic surveillance and manned patrols that can quickly identify and contain any attempts to break through or climb over.
Mr. Forgeard sees potential markets for Airbus-built military refueling tankers, electronic warfare and maritime patrol craft.
Mr Sharon has yet to approve this, but is expected to.The security barricade, begun last year, is a vast territorial barrier, sometimes 100 metres deep, comprising walls, patrol roads, electronic fences and earth trenches.
This would not be a simple fence or wall, but a two-to-three-mile zone of electronic sensors and barriers, patrolled on foot and by helicopter by Israeli defense forces.
Amtrak, meanwhile, increased its own security patrols and intensified electronic surveillance on bridges and tunnels, a spokesman said.
