本論文係探究美國在1950-60年代，亦即杜魯門政府到艾森豪政府任內，其為對抗蘇聯共產集團所採取的圍堵政策之演進。經由研究顯示，圍堵政策的內涵在杜魯門時期從原先的重點圍堵轉變為全面圍堵，而其全面圍堵政策並由之後的艾森豪政府採用。影響圍堵內涵轉變的因素，包含韓戰的爆發、中共介入越戰，甚至是中共完全無視國際準則規範，迫使美國為確保其在國際間的威信等考量，在政策作為上必須由非對稱圍堵進而轉變為對稱性圍堵。這些因素的背後，係取決於蘇聯與中共之間的互動，連帶影響美國決策者改變其對基本國際架構的認知。換言之，肯楠的圍堵概念係植根於兩極國際體系架構而主張重點式圍堵，但隨著中共開始在亞洲對外擴張其影響力，使美國開始在原先被視為是其亞太地區防線的邊陲地帶，如朝鮮半島、中南半島及臺灣海峽等地投入更多資源，令肯楠的非對稱圍堵概念無法適應國際環境變遷，而被尼茲的全面圍堵政策所取代，並反映在著名的國安會第68號文件當中。全面圍堵的概念隨後為來自不同政黨的艾森豪政府所沿用，此亦明顯地反映出，政策的轉變並非導因於政權輪替或政黨歧見所致，而是取決於最高決策者對基本國際架構的認知改變與否。隨著其認知的演變，決策者因而透過進用新的官員以型塑新的執行方針。以圍堵政策為例，圍堵是普遍的政策概念，卻因決策者的認知不同，而型塑出不同的政策內涵及實行面向。
毫無疑問地，蘇聯是美國在冷戰時期的首要敵人，然而所有在亞洲所發生的熱戰，其背後卻大多有著中共的支助。中共的好戰被美國決策當局視為另一個主要的威脅來源，連帶使美國調整過去肯楠式重歐輕亞的重點圍堵，轉變為尼茲式的歐亞並重的全面圍堵。做為區域的強權，中共透過大幅介入鄰近地區的好戰行動足以展現其作為潛在一極的地位。面對中共此舉，早已擠身強權俱樂部的蘇聯在其外交政策與對外作為上則相對的低調以對，此亦使中共對外行為變得更為好戰並更具威脅性。
透過冷戰時期美中蘇三邊的互動，可將中共視為新崛起的潛在第三極。因為不論從地理位置、國力規模、人口數量、更具革命性的意識形態，以及其直接或間接參與的軍事行動而言，中共無疑是新崛起具威脅的一極。美國採取全面圍堵戰略，其目的便是在因應此一具有實際威脅的新興強權。
值得注意的是，特定時期的外交政策方針確實規範著當時政策之規劃及執行。而政策方針係由決策者的認知型塑而成，但決策者亦受到國際架構的轉變而調整其認知。
因此本論文除檢視美國決策者對國際架構認知所型塑出的圍堵政策外，亦將探究不同圍堵政策對臺海之影響意涵以資佐證。筆者將援引國際體系理論分析從兩極體系轉變到三極體系所造成之影響，並輔以聯盟理論探討美國圍堵政策採取聯盟之考量與作為。
隨著圍堵政策之影響仍延續至今，值得重新對其意義和影響加以審視。

This thesis intends to examine the evolution of containment policy by the U.S. against the communist bloc from the 50’s to the 60’s, i.e., from Truman administration to Eisenhower administration. It is observed that the essence of containment strategy had evolved from pointed containment to comprehensive containment during Truman administration and the later strategy of comprehensive containment was then adopted by Eisenhower administration. There were factors such as Korean War, Communist China’s involvement in the Indochina war, Chinese mainland’s complete disregard of international norms, and the ensuing U.S. concern for its prestige that had effected the shift from asymmetric containment to symmetric containment. But underlying these factors were the division of labor between Communist China and the Soviet Union that led the policy-makers to change their perception on basic international structure. In other words, George Kennan’s containment was based on a bi-polar international structure. But as Communist China began to play an increasingly aggressive role in Asia, the U.S. was forced to concentrate more resources in even the originally peripheral areas such as the Korean peninsula, Indochina, and the Taiwan Strait, making Kennan’s concept of asymmetric containment unfit to the evolving international environment and was therefore replaced by Paul Nitze’s version of comprehensive containment-NSC 68. The conception of “comprehensive containment” was then followed by the administration from a different party. It was obvious that the change of policy was not a result of change of administrations or of different political parties’ orientations, but by change of perceptions of top policy-makers on basic international structure. As their perception evolved, policy-makers recruited new crews to shape new guidelines for implementation. Containment is a general policy idea that can be shaped into different directions.
There was no doubt that the Soviet Union was the prime enemy of the U.S.; however, all the hot wars were fought in Asia and the enemies against the “free world” were mostly supported by Communist China. Communist China’s belligerence was seen by U.S. policy-makers as another main source of threat, forcing it to adjust its Kennen-style Europe-first pointed containment to Nitze’s comprehensive containment by gradually shifting strategic weight to Asia. Communist China, as a regional superpower, took a corresponding polar position through its heavy involvement in the threatening activities in its neighborhood. Compared with communist China, Soviet Union, as an established member of the superpower club, was relatively refrained in its foreign policy and behavior. This made communist China’s outward behavior even more belligerent and threatening.
It is assumed that there existed an emerging tri-polar structure in the cold war era. In terms of its geographic location, size and population, more revolutionary ideology, and wars it directly and indirectly engaged, China was no doubt an emerging threatening polar. The shift to a comprehensive containment was a response to an emerging power with a real threat.
It is noted that foreign policy guidelines of a certain time tended to guide policy directions and their implementations for that certain period. As guidelines were molded by perceptions, perceptions were shaped by the evolving international structure.
Besides the examination of containment policies molded by perceptions on international structures, the thesis also studies the implications of various containment policies to the Taiwan Straits to support its arguments. The author was obliged to use the theory of international structure to elaborate the impact produced by evolution from a bi-polar system to a tri-polar system and the theory of alliance to explain the considerations and implementations affecting the alliance behaviors in the U.S. containment policy.
As containment policy’s legacy still lingers, it is worthwhile to reexamine its meanings and implications.