-The United States had successfully detonated the first atomic bomb on July 16, 1945.

- The use of methods of investigation and accusation regarded as unfair, in order to suppress opposition.

-The purpose of the Truman Doctrine was to prevent communism worldwide, explicitly stopping the Soviet Union from expanding its sphere of influence.

-Congress's approval of the Marshall Plan signaled an extension of the bipartisanship of World War II into the postwar years.

-Alarmed by the new U.S. policy of giving economic aid to Germany and other struggling European nations, as well as efforts by the Western Allies to introduce a single currency to the zones they occupied in Germany and Berlin

-American aircrews made more than 189,000 flights, totaling nearly 600,000 flying hours and exceeding 92 million miles

- In some areas, infant mortality rates were one in four. Millions of orphans wandered the burnt-out shells of former metropolises. In the German city of Hamburg alone, half a million people were homeless.

-The Korean War began on 25th June 1950, when communist North Korea invaded South Korea. But its origins lie in the Partition of Korea, which took place at the end of World War Two.

-The statute of limitations had expired for espionage, but he was convicted of perjury in connection with this charge in 1950.

-The Eisenhower Doctrine was a policy enunciated by Dwight D. Eisenhower on January 5, 1957, within a "Special Message to the Congress on the Situation in the Middle East".

- consisting of Cuban exiles who opposed Fidel Castro's Cuban Revolution, clandestinely financed and directed by the U.S. government.

-It was to prevent the Soviets from bringing in more military supplies. He demanded the removal of the missiles already there and the destruction of the sites.

-The expected result is an immediate, irreversible escalation of hostilities resulting in both combatants' mutual, total, and assured destruction.

-The domino theory is the concept that if one domino strikes another, it can lead to a chain reaction where all the dominoes fall. The fear of communism spreading from the Soviet Union, which was America's ally in World War II against Nazi Germany, began after the war ended.

-In that respect, it failed: the two Vietnams were united under a communist banner in July 1976. Neighbouring Laos and Cambodia similarly fell to communists.

-The speech is commonly known by a key line from the middle part: "Mr. Gorbachev, tear down this wall!" Reagan called for the General Secretary of the Communist Party of the Soviet Union, Mikhail Gorbachev, to open the Berlin Wall, which had encircled West Berlin since 1961.

-“Mr. Gorbachev, tear down this wall!” Reagan's stark challenge to tear down the Berlin Wall gave shape to increasing international pressure on Moscow to make good on its promises of openness and reform. The wall, which had become a symbol of Soviet oppression, came down two years later, on November 9, 1989.

-The fall of the Wall marked the first critical step towards German reunification, which formally concluded a mere 339 days later on 3 October 1990 with the dissolution of East Germany and the official reunification of the German state along the democratic lines of the West German Basic Law.