從拜登到川普2.0：美國外交政策與國際領導力之未來和挑戰

From Biden to Trump 2.0: The Future and Challenges of U.S. Foreign Policy and Global Leadership

本研究主要探討川普自第二次入主白宮以來，美國外交政策的發展方向及其對全球領導地位產生的影響。整體而言，川普第二任政府的外交政策在思維與具體作為上呈現出延續與變化並存的特徵。首先，在「美國優先」原則下，強調單邊主義與交易式外交，以追求國家利益的最大化為核心策略。其次，重視硬實力的運用，卻忽視對軟實力的培養與維繫，導致美國國際形象與吸引力持續下滑。
政策上的變化則包括進一步邊緣化既有的多邊國際組織與制度，傾向透過大國間的談判主導全球秩序。其次，其外交政策展現出更為積極的對外擴張意圖，企圖鞏固甚至強化美國在西半球乃至全球各地的主導地位。
在上述外交思維與作為主導下，川普政府不按常理出牌的風格、追求短期利益以及對盟邦與夥伴國家的輕蔑態度與行動，使得美國的對外政策充滿高度不確定性，進一步引發上述國家的焦慮與對美信任的流失。不僅美國的國際吸引力與形象遭到削弱，長期建立的國際領導地位亦隨之動搖，為中國大陸提供了挑戰美國霸權的契機。

This study examines the evolution of U.S. foreign policy following Donald Trump’s return to the presidency for a second term, with particular attention to its implications for American global leadership. The Trump administration’s approach reflects both continuity and change: it reinforces unilateralism and transactional diplomacy under the“America First”doctrine, with an emphasis on hard power while neglecting soft power.
Policy shifts include the further marginalization of multilateral institutions and a preference for great-power negotiations, alongside a more assertive push to consolidate U.S. dominance globally.
These strategies, coupled with Trump's unpredictable style and short-term focus, have generated uncertainty and eroded trust among allies and partners. Consequently, America's international image has declined, and its global leadership position has been weakened, creating opportunities for China to expand its influence and challenge U.S. hegemony.