The name given to the crisis that began with the Islamist students' taking of the American Embassy in Tehran, Iran, is called the Iran Hostage Crisis.

Following the culmination of World War II, the economies of Europe were heavily ravaged by the effects of war. The Marshall Plan, implemented in 1948, was designed to assist these countries economically and re-build them to close to their pre-war strength. The intention was to prevent the Western countries from embracing Communism which was taking hold throughout, the even more impoverished, Eastern Europe.

It was President Ronald Reagan who issued this challenge to the reform-minded Soviet leader, Mikhail Gorbachev. The Berlin Wall eventually fell on November 9th, 1989.

The Pacific Theater was one of the largest extended battlefields in world history. Primarily fought between the United States and the Empire of Japan, as their European allies were occupied in Europe, the battles in the Pacific were largely naval, and in particular featured a great number of aircraft carriers and airplanes, rather than infantry engagements or even tank battles. The Pacific Theater of the war ended fighting when the U.S. dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki, the first use of nuclear weapons.

Planes first became usable after the Wright Brothers' flight in 1903, and were instantly sought for military use. By World War I, all the major countries involved were using planes as military weapons in a number of ways. Despite America also using planes in World War I, the pilots were member of the Army, specifically the Air Corps. This model held until the Second World War, when an increased use of planes showed a need for better organization of their use. In the National Security Act of 1947, the United States Air Force was officially created as a separate branch of the armed forces.

The Kellogg-Briand pact was the brain child of United States Secretary of State Frank Kellogg in 1928. It was a treaty, signed by many nations, including the Soviet Union, which officially renounced war as a means of national policy. Although proposed by a United States’ representative, it did not gain majority support in American society and the U.S. continued to heavily invest in its military throughout peacetime.

Several decades of American interference and militaristic action had soured relations heavily between the United States and Latin America by the time of JFKs inauguration in 1960. To combat this Kennedy proposed a ten-year plan called the Alliance for Progress, which he hoped would halt and reverse this trend. The plan called for political stabilization in the region, economic co-operation and generous American aid. Although the plan did help play a role in the growth of Latin American domestic output in the 1960s and 1970s, lack of support from later Presidents and an unwillingness on the part of many Latin American governments to agree to American proposals ultimately lead the plan to be viewed as a failure.

From 1948, when the State of Israel was first established, until 1978, four large scale wars occurred between Israel and various Arab alliances, typically led by Egypt. By the 1970s, with Cold War tensions driving foreign policy decisions, American leaders sought a deeper peace in the Middle East. In 1977, President Carter invited Egyptian President Anwar Sadat and Israeli Prime Minister Menachem Begin to Camp David in Maryland. There, Carter helped negotiate a framework for a peace agreement between the two nations.

The Axis Powers were, broadly speaking, America's opponents in World War II, but their exact allies were not always straightforward. Upon entering the war in December of 1941, the United States declared war on Japan, Germany, Italy, Romania, Hungary, and other Allied affiliated states. Those countries possessed by Germany were in a different condition, as the German speaking Austrians and Czechs were largely affilliated with the Nazis. France, however, saw a "Free French" army and shadow government form, which was a determined ally of the United States.

All of the answers given were correct. The two specific ones—the sinking of the Lusitania and the Zimmerman telegraph—are likely the most important. The Lusitania was a British passenger ship that was carrying American civilians. The Germans, suspecting it of smuggling arms, torpedoed the ship, killing innocents. The Zimmerman telegraph was essentially a telegraph from the Germans to Mexico asking them to join in an alliance with Germany against the US.