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“They had conceived the McNamara Line, and the sensors for this were now being dropped over the Ho Chi Minh Trail together with mini-mines camouflaged to look like leaves, twigs and things of nature. Acoustic sensors recorded sounds of human and vehicle activity. There were the Button Bombs– pill size explosives which were designed to activate nearby sensors. There was the Lava Plan– an unsuccessful search for a chemical formula to turn the moist forest soil of the Ho Chi Minh Trail into slippery grease…” More>>
