Originally Posted by
Pericles
I won't be able to do justice to the subject in one post, and undoubtedly leave out important detail, but here goes.
At the end of WWII, Germany is occupied, as well as Austria, and as part of the Yalta agreement, elections are to be held in all of the countries of Europe. There were no elections in the Soviet occupied territories, and communist governments are installed wherever the Soviet army was, and that started the concern on the part of the US about Soviet post war intentions.
Civil war between the government and communists start in Greece in 1946, and continues until the government wins in 1948. Also, the Soviets explode their A-bomb in 1947 and Berlin is blockaded to prevent access by the US< UK, and France to their sectors of occupied Berlin. These actions led to public perception in the US, that the Soviets were determined to extend communism to the rest of Europe if not further. Thus the Marshall plan, as an effort to rebuild Europe, in order to turn back the gains that the communist political parties were making in west Europe.
Meanwhile, the China civil war is coming to a close with Mao's victory supported by the Soviets. The US appeared to say that Asia (except for Japan) was not in the US sphere of influence (Dean Acheson January 1950 speech), which was later taken to mean that the US would not intervene in the case of war in Korea. The Korean War started 6 months later. US conservatives took this as further evidence of communist expansionist policy toward world domination. This view is pervasive in the US at this time - partially as an understanding of Marxist - Leninist idealogy (the historical trend is of the struggle of the masses to throw off their oppressive economic systems for a international brotherhood of workers).
The election of Ike in 1952 leads to a change in US policy from proxy war to massive retaliation. This tends to keep the rest of the 1950s relatively peaceful for the US. The launch of Sputnik changes the game again, with the Kennedy accusation that Ike was asleep on the job, and there is now a "missile gap" and the Soviets are achieving superiority in nukes. At the same time, Castro has overthrown the Cuban regime, announces he is a communist in 1961, the Berlin Wall is built in 1961, and the proxy wars are back on in Vietnam, Central America, and Africa.
Summary is that there was an attempt by the communist world to expand - and one can debate to what extent it represented a direct threat of military invasion of the US, if any, but there is a political and nuke threat.
In this context, I'd argue that NATO made sense in that the experience of the US public was that twice in 30 years European wars led to US involvement to end them. Additionally, the "America First" non intervention movement had been discredited by being linked to the Nazis, and working to hinder preparedness (trot out Pearl Harbor vets "never again will we be unprepared"). Clearly what had taken place in east Europe was to integrate those countries into a Soviet led bloc that contributed resources to communist abilities. Without a US security guarantee, west Europe would have felt it necessary to accomodate Soviet expansion.
In the overall context of history, the US participation in NATO played a key role in collapsing a system that was hostile to liberty and the US at a reasonable cost (certainly in life), if not money (certainly cheaper than war).