How did the usa contribute to the collapse of the uusr?

The USA was one of the forces that lead to the overall downfall of the Soviet Union. Starting with the cold war in 1947, the United States and the Soviet Union were engaged in a period of militaristic tensions. The Cold War was an arms race between the two superpowers, and had severe, negative, economic effects on both of the countries. This was one way that the United States contributed to the collapse of the USSR. In addition, the states of the Soviet Union didn't allow their people to leave the country, in fear that they would stay somewhere else. But, when people finally figured out that life might actually be better in the United States, people became angry. A final factor was the Berlin Wall. After World War I, Germany was divided among the Allied Powers: France, Britain, the United States, and the Soviet Union. But, the Soviet Union, in a way, was unhappy with the way that things turned out. So, it decided to build a wall dividing the communist and capitalist parts of Germany. But, like any wall, it couldn't stay up forever. Eventually, a man by the name of Mikhail Gorbachev came along and started new unprecedented ideas, glasnost and perestroika(openness and freedom). This, along with pressure from the United States (namely president Reagan) caused the Berlin Wall to come down, which was a final factor (at least in this list) in causing the Soviet Union to fall.

he sent troops to protect the students as they entered the school.

do u have any answer choices man?