During the time of the "Red Scare" what assumptions were we making about the Soviet Union that would shape foreign policy?

Keep in mind that there were two "Red Scares" in our
history, one essentially soon after the communist revolution and the formation of the
Soviet Union in which we aided "White Russians" in the ensuing Civil War, and conducted
the Palmer Raids in 1919, deporting hundreds of Russians we deemed as people who could
foment a revolution in the US, and a Second Red Scare in the late 1940s and early
1950s.  So our assumption in the First Red Scare was that the immediate Soviet goal was
to spread revolution to the US, who at that time was the largest industrial economy on
Earth.

The Second Red Scare, as detailed above, rested on
two assumptions: 1) that the Soviets were aggressively expanding around the globe and
would only react to the threat of force, and 2) that they had successfully infiltrated
the US government and military, an assumption which led to McCarthy's hearings in the US
Senate.