雖然艾森豪政府在兩次危機都沒有啟動軍事行動，然而軍事行動甚至是核子武器一直都是備案，各組織都盡最大努力希望其建議會受總統採用，如果案子被化為政策執行軍事行動，就可以使將其組織之價值凸顯出來。這樣的情形特別是第一次台海危機的核子武器使用上更為明顯，原因是當時在大規模毀滅的策略下，大部分的軍種對執行該任務都很有興趣。然而此種情形在第二次台海危機時，起了一些變化。由於當時蘇聯之核武器已發展成熟，所以在第二次危機時，美國對使用核武器的態度相對保守很多。總的來說，美國對此兩次台海危機的外交策略雖有一些調整，但所有的政策及策略，都是以美國最大的利益為準。 The paper laid the foundation on Graham T. Allison’s three decision-making models-the Rational Actor Model (RAM), the Organizational Behavior Model (OBM), and the Governmental Politics Model (GPM) as the theoretical structure to explore the formulation of U.S. foreign policy during the two Taiwan Strait Crises in the 1950s. In order to make the analysis more comprehensive, I also adopted the comparative analysis method to present the evolution of the decision-making process of the two Crises. By doing so, I established three hypotheses from the theory and applied them in the two case studies to verify application of the theory. When these offshore islands were under heavy attack in the first Strait Crisis, whether or not the U.S. should defend these offshore islands for Taiwan was “ a horrible dilemma” to the Eisenhower administration and put the U.S. in a difficult situation to deal with due to its extensive political implications. On the one hand, the U.S. was unwilling to run the risk of waging war with Communist China or even Soviet Union. On the other hand, it did not want to lose its prestige because of staying out of the Strait conflict. Considering all the courses of actions, the U.S. attempted to resolve the Crisis by passing the dilemma to the U.N, signing the Sino-U.S. Mutual Defense Treaty and concluding the Formosa Resolution with Taiwan in exchange for ROC’s acceptance of the U.N. arrangement and withdrawal from Tachens. When the second Crisis occurred in 1958, with nearly one third of ROC troops stationed on the islands, the dilemma therefore was not to intervene or not but how to intervene to suit U.S. best interest. The Eisenhower administration decided to provide escort operation for safety landing of ROC’s supplies. Although the Eisenhower administration did not take military actions in the event of both Strait Crises, utilization of nuclear weapons as well as military actions were widely discussed and prepared. Various organizations had tried to have their proposals of military actions adopted by President Eisenhower so that they could stand out their organizational values. In particular, the employment of nuclear weapons was seriously considered under the ”Massive Retaliation Strategy.” While in the 1958 Crisis, the posture of Eisenhower administration toward utilization of atomic weapons became relatively conservative in light of the Soviets progress of its nuclear weapons. The overall policy of Eisenhower administration did undergo some changes; nevertheless, the adjustments all served U.S. best interests.