The 1961 Bay of Pigs fiasco involved CIA-backed rebels landing in Cuba to overthrow Fidel Castro. The promised U.S. air support never happened, and Castro knew where they were landing. The invasion force was wiped out;
Also in 1961, the East German government erected a wall splitting Berlin in half. The eighty-mile-long wall was made of concrete, barbed wire, and mine fields;
In 1962, the Soviet Union tried to base Intercontinental Ballistic Missiles (ICBM) in Cuba. The U.S. government found out, and the world waited for nearly two weeks as the superpowers squared off. The U.S. issued a quarantine that allowed for American personnel to board Soviet ships that got too close to Cuba. Eventually, Soviet premier Khrushchev agreed to pull his missiles out in exchange for the U.S not invading Cuba and removing missiles based in Turkey;
The following year, the CIA backed a coup in Iraq, which eventually gave rise to the Baath Party and Saddam Hussein; and
Kennedy increased U.S. presence in Vietnam to more than 16,000 men. It appears he was considering a withdrawal of U.S. forces at the time of his assassination.