本文的研究目的在於觀察美國總統歐巴馬任期內的美日同盟關係之互動，並加入當前國關學界對於「同盟政治」以及東亞區域安全課題的討論。由此，在研究過程中，首先詳述美國與日本的國家安全戰略與外交立場，以及兩國之間的互動如何有效維繫彼此的同盟關係。 在具體研究步驟上，同盟內部協調能力與面臨外在情勢的同盟凝聚力是本文主要探討的的兩大重點。本文首先將美日關係中的安全、政治與經貿議題當作同盟的內部因素，檢視美日同盟之間的合作與分歧議題，以及美國總統歐巴馬與日本首相之間的互動過程，藉此評估美日同盟的協調能力；另以中國因素做為外部因素，討論中國對於美日同盟的各項影響，再以案例分析，檢視美國處理中日爭執議題的立場與實際作為，觀察美日同盟與中國之間的互動過程，藉此檢視美日同盟的凝聚力。最後部分則總結美日同盟在歐巴馬總統任期內的整體變化與效能分析。 / This research focuses on the alliance politics of the US-Japan alliance in the Obama administration. From 2009 to 2014, the Obama administration has faced five different Japanese cabinets, both the governments of the US and Japan had different perceptions regarding the alliance cohesion and coordination. These perceptions, in addition to their political, economic, and secure interactions have created multiple impacts on the US-Japan alliance. The China factor is another key issue during this research. Although China and the United States are very far from being adversaries as they were in the beginning of the Cold War era, they do engage in issues like South China Sea, East China Sea, and the global economic competition. The Obama administration is also trying to avoid the alliance security dilemma—the risk of entrapment and the cost of abandonment—with the malign China-Japan relations. Besides, this research further investigates how the US-Japan alliance has adjusted itself to the changes and challenges in the global and the East Asia regional security.

安倍自2012 年12 月第二次執政後，要讓日本成為世界大國的目標十分明確。 首先以經濟政策穩定國內政權，同時巧妙地以新現實主義作為基礎，充分利用「制 衡」與「同盟」兩種戰略，一方面因地緣政治而深受中國、北韓、俄羅斯等國強 大壓力威脅，反而利用這樣的威脅對國內民眾灌輸強國意識，合理提高防衛預算、 改革防衛裝備移轉機制、增兵西南諸島並強化整體軍備實力等實質。 另一方面利用美國畏懼中國取代而成為亞太霸權的心理，以及日美同盟長久 以來奠定的良好聯合作戰架構，讓美軍充分涉入亞洲戰略區域情勢中，這樣的兩 手政策，就是安倍首相朝向「正常國家化」而努力推動修憲的最明顯手法。本研 究就亞太週邊環境對日本造成的威脅，試圖導出安倍防衛政策的背景因素與結構 性變化的關鍵原因，並理解政策的邏輯與內涵，以判斷日本於亞太區域環境中的 行為模式。 / Prime Minister Shinzo Abe has clearly made his intent for Japan to become a big power since his second term starting from December 2012. To attain this goal, he first enforced financial policy in response to domestic economic chaos, meanwhile adopted “Balancing＂ and “Alliance＂strategies in accordance with“neo-realism＂ based onits strategic theory.In one hand, Abe uses the geopolitical threat formed by China, North Korea and Russia to rationalize his policies of raising national defense budget, reforming armament transfer principles, increasing force deployed on Japan＇s southwest islands and strengthen overall defensive capability. On the other hand, he carefully uses the U.S. fear China may replace it as the Asia-Pacific hegemony, and that U.S. needs firm coalition with Japan, keeping U.S. much involved with the power-pursuing game in Asia. This research intends to discover the key factors that results in Abe’s current defense policy and its structural change, while to understand the logic and processes of policy-making process, in order to identify how and what Japan will conduct in the Asia-Pacific area.