Strategic Defense Initiative

The Strategic Defense Initiative (or SDI) was a program creating a network of land and space-based anti-missile defenses on Earth, intended to neutralize any international offensive missile attacks. It was initially proposed in 1983, and was given the nickname "Star Wars", after a popular film series of the day.

The SDI network was deactivated with the signing of the United Earth Accords. It was the last space-based military system directed at Earth, as opposed to extraterrestrial threats. 


 * In reality, SDI has never been fully implemented, and has gone through several name and mission objectives changes since the publication of Strangers.