Since the end of World War II, the US military has continuously deployed troops to South Korea. The alliance works as an asymmetrical alliance, where the US is a patron and South Korea is a protégé. While it is argued that this deployment has significant political, economic, and military effects on South Korea and the region, few studies have examined how the presence of US forces there enhances US military and economic power as well as national security interests. In this paper, we examine the costs and benefits of the US–South Korea alliance, specifically focusing on US troop deployment on the Korean Peninsula. In particular, we argue that the US military alliance with South Korea has significant benefits to both partners, but particularly for the sake of US national security interests. In this sense, the protégé state provides significant benefits to the patron state. We discuss the strategic importance of South Korea in US foreign policy in the region and emphasize the benefits of the US–South Korea alliance at the various levels.

二战结束以来，美军不断向韩国部署军队。该联盟是一个不对称的联盟，美国是赞助人，韩国是门生。虽然有人认为这种部署对韩国和该地区具有重大的政治、经济和军事影响，但很少有研究考察美军在那里的存在如何增强美国的军事和经济实力以及国家安全利益。在本文中，我们考察了美韩联盟的成本和收益，特别关注美国在朝鲜半岛的部队部署。特别是，我们认为美国与韩国的军事联盟对双方都有重大好处，尤其是为了美国的国家安全利益。在这个意义上说，保护国为保护国提供了重大利益。我们讨论了韩国在美国在该地区外交政策中的战略重要性，并强调了美韩联盟在各个层面的好处。