President Reagan suspected that the announcement of the Strategic Defense Initiative (SDI) would infuriate the Soviet Union. He was right. Despite Reagan's repeated assurances that the defense system would only be used to prevent the Soviet Union from attacking rather than giving the U.S. carte blanche to strike without consequence, Soviet leader Yuri Andropov remained unconvinced. Within a year, the Soviets were directing 70 percent of their propaganda worldwide toward maligning SDI, despite finding the program not feasible to begin with [source: Lettow].
The Soviets also pointed out that any ballistic missile defense system the United States could build would violate a number of treaties already in place. For instance, the Anti-Ballistic Missile (ABM) Treaty of 1972 limited both the United States and the Soviet Union to two (and later one) ground-based missile defense systems. The 1967 Outer Space Treaty, signed by several countries including the U.S. and the Soviet Union, banned the use of weapons of mass destruction in space.
The firestorm of criticism for Reagan's plan kept burning. European allies were concerned about how the program would affect the precarious balance of power between them and the Soviet Union. U.S. lawmakers worried that the technology needed to shoot ICBMs down midflight was simply out of reach and not worth pursuing. These fears from home and abroad introduced some serious tension into negotiations among all parties involved. Still, despite serious pressure to put SDI on the bargaining table in an effort to get the Soviet Union to reduce its nuclear armament, Reagan refused to compromise the program.
Subsequent presidents, however, were quick to modify and cut the program. President George H.W. Bush initiated a review of SDI shortly after the start of his term, ultimately deciding to refocus the program and drastically cut back its scope. Granted, by this time the Soviet Union had collapsed, diminishing the threat of large-scale nuclear war. Rapidly rising costs and relatively few tangible results had also made the program more unpopular than ever. President Bill Clinton further refined the scope of the project, and before long, the United States' missile defense programs looked very little like what Reagan envisioned when he announced the program. Of course, things might have gone very differently for SDI had the technological aspects of the program not been so daunting.
Read on to see exactly how SDI hoped to shoot down nuclear missiles, and how those hopes never quite turned into reality.