What describes the changing relations between the Soviet Union and the United States between 1917 and the 1950's?U.S History papers

I think the best way to describe this is to say that
relations between the two countries started out very badly, got better, and then got
worse again.

After the revolution in 1917, the Soviet Union
came to be and the US would not recognize it as a country.  The US even tried to help
overthrow it.

But then, during World War II, the US and the
Soviet Union became allies.  This happened because we thought Hitler was a greater
threat.

After World War II, the Cold War started and the
two countries became enemies for decades.