影響一九四九至一九五○美國對臺政策的政府內部因素就屬軍方和國務院的爭辯。造成雙方在對臺政策上產生重大岐見的原因，除了雙方各自的本位主義之外，影響最大的就是對中共的認知不同。在此一期間，美國對臺政策可分為三個時期：一、確保臺灣時期（一九四八年十二月至一九四九年十月）；二、對臺「袖手旁觀」時期（一九四九年十月至一九五○年二月）；三、重新檢討對臺政策時期（一九五○年二月至一九五○年六月）。此時美國對臺政策的制定是隨著中國現地情況的步伐在走，每一個分期都緊扣著當時中國的局勢。在三個分期中，軍方和國務院對於對臺政策的看法上可說是各有定見，雙方在對臺政策的制定過程中有著精彩的攻防。本文即從政策爭辯的角度來看一九四九年至一九五○年的美國對臺政策，希望能找出爭辯的主因。

The disputes between the military and the Department of State are the inner factors of U.S. government that influenced its policy to Taiwan between 1949 and 1950. In addition to their shared egoism, the different recognition of China is the primal reason which leads to the disputes. During this period, there are three-step development in U.S. government's policy to Taiwan: 1. sustaining the separate status of Taiwan from China (from December of 1948 to October of 1949); 2. the outsider period (from October of 1949 to February of 1950); 3. reconsidering its policy toward Taiwan (from February to June of 1950). During that period, US's policy to Taiwan was always based on reflecting on the status quo of China. Furthermore, in the process of decision making, both of military and the Department of State insisted on their own perspective options in the policy to Taiwan, and thus incurred great disputes between them. This article focuses on the "political dispute" by analyzing the U.S. government's policy to Taiwan between 1949 and 1950 and explicating the main reason that cause disputes between the military and the Department of State.