“Even one war in space will create a battlefield that will last forever, encasing the entire planet in a shell of whizzing debris that will thereafter make space near the earth highly hazardous for peaceful as well as military purposes. With enough orbiting debris, pieces will begin to hit other pieces, whose fragments will in turn hit more pieces, setting off a chain reaction of destruction that will leave a lethal halo around the Earth.” – Joel R. Primack and Nancy Ellen Abrams, “Star Wars Forever?—A Cosmic Perspective”