"For more than three decades, beginning soon after the end of World War II, the United States and the Soviet Union faced off against each other. The concept of 'mutual assured destruction'--MAD, the U.S. threat of massive retaliation to a Soviet first strike--became America's Cold War de facto strategic defense policy. In March 1983, however, President Ronald Reagan asked whether ballistic missiles could be destroyed before they reached the United States or its allies, thus catalyzing efforts for a national ballistic-missile-defense program that would undermine the need for MAD. That same year, the U.S. Navy commissioned USS 'Ticonderoga' (CG 47), the first of what is to become a fleet of more than eighty Aegis warships. In 2012, these trends have converged, and Aegis ballistic-missile defense (BMD) is an increasingly important component of a robust national BMD System (BMDS). National BMDS has morphed from President Reagan's original vision of a system to deter and, if necessary, defeat Soviet intercontinental ballistic missiles (ICBMs) to one focused on deterring or defeating shorter-range ballistic missiles fired at the United States or its allies and friends by rogue nations or terrorist groups. So too the 'pillars' of the national BMDS have changed. As other air, ground, and space pillars have advanced in fits and starts, and as related programs have been initiated and, sometimes, canceled, the seaborne component of national BMDS has become an increasingly central component of U.S. regional ballistic-missile defenses. Aegis BMD is now moving toward a role in the defense of the American homeland as well."
2012 Brad Hicks, George Galdorisi, and Scott C. Truver
Naval War College Review: http://www.usnwc.edu
Naval War College Review (Summer 2012), v.65 no.3, p.65-80