二次大戰以來美歐同盟主導著國際政治舞台。2010年代大西洋兩岸政治發展的許多現象，包括英國脱歐、美國自2016年起由政治素人川普掌政、民粹在2016至2018年間的許多歐洲大選包括德奥義法大有斬獲等，影響了當地國内政治的同時也改變了國家對外政策，進而衝擊了跨大西洋關係。本文觀察2010年代，主要爲英國脱歐公投及川普掌政後，大西洋兩岸在安全合作及經濟合作上的發展，包括大西洋兩岸透過北約的合作及歐盟與北約的競合，以及美歐近期在TTIP談判上的挫折，發現美歐關係在安全上的調整比經濟上的調整來得更爲迅速順利。造成美歐關係在安全與經濟發展不同速的主要原因有二，其一爲反全球化引起的泛政治化效應對於國際經濟合作的質疑，其二爲美歐關係在政治與經濟上的關係本質差異一政治面爲依賴關係，而經濟關係則是既合作又競爭。未來美歐關係的挑戰一則是如何回應反全球化浪潮對於國際合作的質疑，一爲如何在英國脱歐後調整美歐英三角，重新鞏固大西洋關係。

US-Europe alliance has influenced the international relations since the second world war. Recent national elections in the US and in Europe, including those in Germany, Austria, Italy and France etc., reflected the rising of populism and questioned the globalization and current political regimes. The national elections above would not only decide the domestic politics but also influence foreign policies and US-Europe alliance. This research discusses the security and economic developments in the transatlantic relations, including the cooperation in the NATO and the competition between the EU and the NATO, and the frustration in the TTIP negotiation in recent years, finding that the adjustment in the security perspective is much quick than that in the economic one. The variation is due to the politicization in international economic cooperation issue causing by anti-globalization and the different natures of economy and politics of transnational relations. The nature of political relations is dependency, while that of economic relations is competition and cooperation. The future challenges of transatlantic relations are, how to respond to the question of anti-globalization, and how to adjust the US-EU-UK triangle after Brexit to rebuilt the transatlantic alliance.