The resulting proposal called for deforesting 80 to 90 percent of a crucial 180-mile portion of South Vietnam’s border with Laos that formed a part of the Ho Chi Minh Trail. A handwritten list of proposed technologies was indeed novel, if in some cases horrifying. The barrier would require 100,000 “throw-away” shotguns, 250,000 rocket pistols, one million tetrahedrons (ground-based spikes, also known as caltrops), two million mines disguised as rocks, twenty thousand bomblets loaded with chemical defoliants, and an unidentified amount of “insect attractants” (as opposed to insect repellant).
