Korea was divided into two, North Korea and South Korea. North Korea established a communist government and invaded South Korea. At the same time, America wanted to contain communism, so they sent troops over to help South Korea. The U.S. army defeated the North Korean troops that were in South Korea and advanced into North Korea. China entered the war on North Korea's side. The Korean War eventually ended with both sides being split just like before.
Iran Hostage Crisis (1979-1981)
Fidel Castro and his fighters overthrew the dictator of Cuba and took control. Castro turned Cuba into a communist dictatorship country. Castro's government started taking over people's property, and when he took control of property belonging to American companies, the U.S. cut off trade with them. Then, the CIA trained Cuban exiles to go and eliminate Castro. On April 1961, the exiles landed at the Bay of Pigs, but they ultimately failed to complete their mission and were defeated.
The First Gulf War (1990-1991)
After the Bay of Pigs, Castro grew closer to communist Soviet Union. One day, American spy planes discovered missile bases in Cuba, only 90 miles from Florida. Kennedy established a naval blockade of Cuba and demanded that the missiles be removed or he would attack Cuba. Soviet leader Khrushchev promptly removed them, and the U.S. removed missiles they had in Turkey.
Second Gulf War (2003)
The Iranian people overthrew the ruler of Iran and installed a new republic. The ruler fled to the United States to seek medical attention. The Iranian leaders objected this, so they let an angry mob capture the staff of the U.S. Embassy. They held them as hostages for over a year. President Jimmy Carter was able to negotiate their release, and they were let go in January 1981.
Saddam Hussein was the leader of Iraq. He invaded and occupied the country of Kuwait because it was rich in oil. President George H.W. Bush put together an alliance of countries to oppose Hussein's invasion. The allied forces were able to defeat the Iraqi forces and freed Kuwait.
Saddam Hussein continued to rule over Iraq. America had just recently fallen victim to a terrorist attack, known as 9/11. President George W. Bush was worried that Hussein might be hiding weapons of mass destruction, so Bush demanded that Hussein be removed from office. Hussein refused, and the U.S. invaded Iraq. Hussein fled but was captured. American troops could not leave Iraq after the invasion, so they faced Hussein's supporters, Islamic Fundamentalists, and other groups. Obama eventually withdrew the troops in 2011.