Cho những ai thích tìm hiểu về quân sự/tình báo/vũ khí và Vietnam War:

Cho những ai thích tìm hiểu về quân sự/tình báo/vũ khí và Vietnam War:

"From its intelligence work a year earlier, the CIA knew about a weak point in the North Vietnamese wall of security: a telephone line used by the country's military commanders, located near the industrial city of Vinh. A patrolled bicycle path ran alongside the string of telephone poles, but at one spot, about 15 miles southwest of Vinh and just east of the Cau River, the phone line went straight up a bluff, over a ridge, and down the other side. The terrain was too steep for bikes, so the path followed the river, which flowed around the bluff, rejoining the telephone poles on the bluff's far side (see hand-drawn map, p. 67). This would be the best place to drop off commandos to place a wiretap."
http://www.airspacemag.com/military-aviation/air-americas-black-helicopter-24960500/?all&no-ist