The correct answer is: "all of the above"
In the Cold War era, the US had adopted the containment strategy that aimed to stop the expansion of communism and of the influence of the URSS throughout the world. Instead, the US promoted democratical goverments and liberal market economies. It was crucial for the US to expand its influence over Western Europe and to keep the region strong, as the URSS already had many Eastern European countries under its orbit, which had become soviet republics.
Moreover, URSS and US started parallel arms races and they fiercely competed in this field, aiming to demonstrate which one was actually the main world superpower.
