B-1(B) bomber: Manned U.S. intercontinental bomber. Program canceled by Carter Administration but resurrected under Reagan with redesigned aircraft known as B-1B.

Bay of Pigs: An unsuccessful invasion of Cuba by 1500 Cuban exiles with U.S. Government support on April 17, 1961.

Berlin Airlift: The supply of vital necessities to West Berlin by U.S. aircraft from June 1948 through September 1949. The Soviets had hoped to force Allied abandonment of the city by establishing a water and land blockade, but the constant flow of American planes, totalling 277,000 flights with more than 2 million tons of supplies, kept West Berlin alive.

Berlin Wall: The fortified barrier erected by the East German government in August 1961 to divide East and West Berlin and halt the exodus of East Germans fleeing Communist rule.

BOMARC: Boeing Michigan Aeronautical Research Center; also surface-to-air anti-aircraft missile designed at BOMARC.

Bomber gap: The fear of Soviet superiority in the area of intercontinental bombers, which first arose in July 1957 after Soviets flew their Bear and Bison bombers past American observers multiple times, duping them into exaggerating Soviet capability.

Brussels Pact: Signatories of the Brussels Treaty, a 50-year treaty of economic, social, cultural, and defensive collaboration between Belgium, France, Luxembourg, the Netherlands, and the United Kingdom, signed March 17, 1948.

Carter Doctrine: President Carter's commitment to defend U.S. interests in the Persian Gulf, motivated by the Soviet invasion of Afghanistan.

Checkpoint Charlie: The American checkpoint and guardhouse at the border of East and West Berlin.

Containment: U.S. Cold War foreign policy toward the Soviet Union, first articulated by George Kennan in 1947 with his famous "X" article in Foreign Affairs. As originally articulated, the policy called for a vigilant but patient reaction to Soviet expansionism, emphasizing political and economic tools over military force.

Cuban Missile Crisis: The major Cold War confrontation between U.S. and Soviet forces over the deployment of Soviet IRBMs in Cuba in 1962. An American naval blockade and high alert status ensued until the crisis was defused by the removal of the Soviet missiles and an American pledge to dismantle IRBMs in Turkey and to never invade Cuba.

Detente: A lessening of tensions between the superpowers, primarily associated with the 1970's. The term is used loosely to describe either a situation or a policy.

DEW line: A distant early warning line of radar and communications equipment deployed along northern Alaska and Canada designed to detect and track Soviet ballistic missiles.

DMZ: De-Militarized Zone; refers to the unoccupied strip of land at the 38th parallel that divides North and South Korea.

Executive Order 12356: The current Executive Order setting protocol for the declassification of government documents.

Flexible response: A military strategy adopted by President Kennedy and Defense Secretary McNamara calling for a graduated escalation of force in response to aggression, in contrast to the previous doctrine of massive retaliation.

FFRDC: Federally funded research and development contractor.

FOIA: Freedom of Information Act. Federal legislation codifying the responsibility and protocol of Federal agencies for the provision of public access to government records.

HABS/HAER: Historic American Buildings Survey/Historic American Engineering Record.

Hawk Missile: "Homing all the way Killer," American surface-launched anti-aircraft missile.

ICBM: Intercontinental ballistic missile.

ICOMOS: International Council on Monuments and Sites.

INF: intermediate range nuclear forces. The 1987 INF Treaty, a landmark arms control agreement, provided for the removal and destruction of all INF weapons in Europe.

IRBM: intermediate range ballistic missile.

Iron Curtain: Term first used by Winston Churchill to describe the political barrier which had been erected between the East and West and the creation of spheres of influence.

Jupiter Missile: An early American IRBM. A squadron was removed quid pro quo to de-escalate the Cuban Missile Crisis.

Man in Space: National Historic Landmark theme study to document and preserve relics and resources of the NASA space program.

Massive retaliation: Eisenhower's military doctrine of threatening a full nuclear retaliatory response to any perceived aggression against U.S. interests; later replaced by flexible response because of its lack of credibility.

McCarthyism: The practices of Senator Joseph McCarthy to discredit American citizens through sensational and unsubstantiated accusations of Communist complicity.

Military-industrial complex: A phrase first coined by President Eisenhower in his 1961 farewell address describing the close linkage between the U.S. military and private contractors in the military industry.

Minuteman II: American ICBM entered into service in 1966.

Missile gap: The perceived Soviet superiority in ICBMs due to exaggerated estimates by the Gaither Committee in 1957 and USAF in the early 1960's.

MX missile: The most advanced U.S. ICBM in service, now known as the "Peacekeeper." It was supported by Carter and first deployed under Reagan in 1988.

National Security Act of 1947: This reorganization of the U.S. defense establishment created the office of the Secretary of Defense, the National Security Council (NSA), the Central Intelligence Agency (CIA), and the U.S. Air Force (USAF).

NIKE: A U.S. Army project begun in 1945 to develop missiles for air defense. Several NIKE missiles were developed and deployed, including the NIKE-Ajax and NIKE-Hercules.

NSC-68: An important U.S. foreign policy document of 1950, which reappraised America's global position vis-'a-vis Communist China and the Soviet Union. It called for a full-scale military build-up to confront Communism, which it saw as a monolithic force bent on world domination. It stressed the need to confront Communists anywhere in the world at any cost, as a gain for the Soviets would be regarded as a loss for America.

Rand Corporation: A government-sponsored "think tank" created in 1946 to study problems of national security.

Rapid Deployment Joint Task Force: Carter authorized the creation of this force of up to 200,000 troops for response to military emergencies around the world, primarily in response to the Soviet invasion of Afghanistan.

SAC: Strategic Air Command; a now defunct component of the USAF with the mission of delivering Air Force strategic nuclear assets to targets overseas.

SALT I: Strategic Arms Limitation Treaty; signed in 1972, it froze numbers of ICBMs and SLBMs in place for 5 years and restricted the deployment of ABMs.

SDI: Strategic Defense Initiative; an ABM research program dedicated to finding technology to destroy incoming ICBMs. It was begun in 1983, after Reagan's "Star Wars" speech in which he called on the nation's scientific community to "give us the means of rendering these nuclear weapons impotent and obsolete . . ."

Sentinel: A proposed ABM system designed to defend cities against ballistic missile attack.

SOFA: Status of Forces Agreement; SOFAs, which establish legal rights and protocols, are negotiated between the United States and each country in which American forces are deployed.

Space race: The superpower competition in space exploration technology that paralleled the Cold War competition in arms developments.

START: Strategic Arms Reduction Treaty.

Titan II Missile: An early U.S. ICBM, now decommissioned.

Trinity Site: Site of the first U.S. atomic bomb test, now listed on the National Register of Historic Places.

Truman Doctrine: Truman pledged in 1947 to defend "free people who are resisting armed subjugation by armed minorities or outside pressures." The policy was aimed at providing economic and military support to those European countries which were fighting Communist takeover at the time, especially Greece and Turkey.

Warsaw Pact: Signed in 1955, it codified the East-West split and provided for mutual defense among Albania, Bulgaria, Czechoslovakia, East Germany, Hungary, Poland, Romania, and the Soviet Union.