Further research into this led me to this interview:Werner von Braun knew that space weaponry was being planned decades ago, and that an ET threat would be used to justify weapons in space. In his last years, he fought against space weapons.
According to Von Braun's sequence of rationalization, the Americans would use a progressive chain of enemies: Russians > terrorists > Third World crazies > asteroids > extraterrestrials to justify their use of space weaponry. Von Braun said that the rationales would accelerate until they would suddenly be a 'fait accompli'.
http://www.nancyredstar.com/wmd/Anti_Satellite.htm (scroll down)