-This was our major justification for U. S.
foreign policy during the Cold War?

It is the containment doctrine. It saw the Soviet Union as a great power with a totalitarian ideology that aimed at world hegemony and expansion. Soviet ideology proposed a state-dominated economy, supression of private property and one-party rule. It was the anti-thesis of Western democracy and a free-market society. The doctrine called the United States to oppose communist expansion globally by all means available - diplomatic, economic and military. The US had to lead the West to contain the USSR and communist expansion; in the long run, the communist system would implode, the doctrine assumed under the burden of its own contradictions. And that´s what exactly happened in 1989-1991.

Explanation:

assessment is the missing word