The main pillars of U.S. foreign policy during the Cold War were as follows:
1) Contain Soviet expansionism: Concern about the Soviet Union's intentions and capabilities for expanding its influence beyond the borders of the Warsaw Pact military alliance was the central pillar of U.S. foreign policy throughout the Cold War. It's conceptual father was a senior foreign service officer stationed in Moscow named George Kennan, who wrote a document known to history as "the Long Telegram." This document outlined for his superiors in the Department of State the basic tenets of Soviet foreign policy, why those tenets were threatening to U.S. interests, and how best to limit the Soveit Union's ability to spread its influence. Kennan subsequently submitted an article to the prestigious journal "Foreign Affairs" under the pseudonym "X" rearticulating in more concise form the main themes of the Long Telegram.
2) Deter nuclear war: Throughout the Cold War, the United States sought to engage the Soviet Union in a series of agreements designed to place limits on the number and types of nuclear weapons in each countries arsenal. Concerns about a nuclear arms race, well-founded during the 1960s, and about the threat such a race posed to civilization placed a premium on the conclusion of arms control agreements. These agreements covered a range of nuclear weapons related areas, including a prohibition on testing nuclear weapons above ground, how many long-range, or intercontinental (so-called because they could reach each other's territory when launched from within their respective borders), missiles each side could have, and placing limits on defenses against each side's long-range missiles so as not to facilitate the further growth in arsenals.
3) Spreading democracy: U.S. foreign policy vascillated during the Cold War with regard to the role the U.S. should or shouldn't play in facilitating the spread of democratic forms of government. With half of the world subjected to totalitarian governments in which basic freedoms were nonexistent, there were many in the United States foreign policy establishment who believed the United States had a responsibility to help the citizens of these countries fight for freedom. Especially during the first half of 1970s, U.S. foreign policy became less idealistic and more steeped in what was known as the "realist" school of thought. Ideals were less the driving force of foreign policy and cold, hard calculations of national interest assumed a greater place in policy circles.
There are many components of these pillars that were not discussed due to time constraints. The Marshall Plan for the rebuilding of post-World War Europe, Mutual Assured Destruction, the role of the Vietnam War, the Carter Administration's emphasis on human rights, the Soviet invasion of Afghanistan, all were major factors or policy decisions that played a large role in how foreign policy was conducted during the Cold War.