Kill Chain: The Rise of the High-Tech Assassins Read Online Free PDF Page A

not be a physical barrier but something never seen before in the world: an invisible electronic network that would detect, identify, and destroy any enemy seeking to cross it.
    The first stage consisted of arrays of sensors distributed across the jungle. Some were acoustic, microphones listening for the sound of trucks or footfalls or voices. Others were seismic, ready to detect movements of these same trucks or people. Yet more “sniffed” the air for telltale traces of ammonia, denoting urine and therefore people. Another variety was on the alert for the ignition spark of an engine. If and when a sensor picked up an indicator of enemy presence, it would transmit the signal to planes circling constantly overhead, which would in turn relay the message to distant computers programmed to sift through the necessarily ambiguous information—a column of troops or a herd of elephants?—and match up the apparent source of the signals with the map of enemy trails implanted in the computer memory. To process the data Garwin, the IBM scientist, recommended the IBM-360 computer to analyze the signals, he explained, and “try to characterize the sounds so you wouldn’t be bombing birds or peasants but convoys, trucks, or whatever.” Once birds and peasants had been eliminated, promised Garwin, the computer would order “response, immediate response” from attack aircraft. (Even though they were dealing with the movements of humans and trucks, the scheme echoed their solutions for detecting and intercepting incoming Soviet missiles.)
    This was no casual back-of-the-envelope scheme. Ensconced in Santa Barbara, the scientists, with occasional breaks for surfing or walks on the beach, delved deep into finer details, such as the necessary camouflage for sensors impaled on spikes in the ground (disguised to look like weeds native to the area) and munitions suitable for use against enemy formations once they were located. Their preferred choices were SADEYE/BLU-26B cluster bombs, which blew open after release to disburse 600 yellow shrapnel bomblets over a radius of 800 feet. For sensors, they recommended acoustic devices adapted from the traditional microphone-equipped buoys used by the navy when searching for submarines. Since these might fail to pick up the sound of sandal-clad Vietnamese or their trucks, the area would also be seeded with 300 million tiny firecrackers the size of aspirins. When detonated by a rolling tire, or a stealthy footfall, they would make a sharp bang and so trigger the sensors. The cost of the entire effort was estimated at about $800 million a year (roughly $10 billion in 2015 dollars), which they deemed a bargain because the war would consequently “taper off.” In any case this initiative was positively humane, in the scientists’ view, compared to the wholesale bombing of North Vietnam then underway.
    In September, leading Jasons returned east to brief Defense Secretary Robert McNamara on the carefully thought-out scheme. The secretary, who was very fond of neat technical solutions to human problems, was highly enthusiastic and ordered the air force to get to work immediately. Though initially irked at having an operation dreamed up by civilian eggheads foisted on them, the service chiefs soon reconciled themselves to the limitless funds available, and by mid-1967 the system was largely in place.
    F-4 fighter-bombers and other aircraft strewed hundreds and then thousands of sensors across the jungle. Fleets of assorted aircraft were deployed to circle day and night and relay radio signals from the sensors back to Nakhon Phanom, a military base on the west bank of the Mekong River in northeast Thailand that was so secret it officially did not exist. The base hosted a whole variety of unacknowledged “black” activities, but at its heart, behind additional layers of razor wire and guard posts, sat an enormous air-conditioned building, the largest in Southeast Asia, that was home to Task Force Alpha,