The Republic of Korea (ROK) and the United States are redefining their alliance to meet emerging challenges, including an emphasis on broader Indo-Pacific cooperation and strategic flexibility. The update seeks to enhance deterrence on the Korean Peninsula while positioning the alliance as a pillar of regional security.
In May 2025, Gen. Xavier Brunson, commander of U.S. Forces Korea, described the ROK as “an anchored aircraft carrier between Japan and China,” highlighting a move away from a peninsula-focused mission to regional engagement.
Meanwhile, Seoul is developing capabilities to support such broad operations. For example, the ROK Navy in February 2025 established the Mobile Task Fleet, “consisting of more than 10 large surface combatants capable of conducting offshore maritime missions,” Dr. Kim Jae Yeop, a senior researcher at the Sungkyun Institute for Global Strategy in Seoul, told FORUM. The fleet includes four Aegis destroyers and is a major step toward the ROK’s vision of becoming a naval power.
The nation’s air power is similarly expanding with the introduction of European aerial refueling aircraft and plans to acquire Brazilian transport planes. “These assets will support Seoul’s combat aircraft missions [with] extended range. Furthermore, they can also take a role as long-range cargo planes for overseas mobility activities, like humanitarian relief,” Kim said.
President Lee Jae-myung, who took office in June 2025, has prioritized increasing Seoul’s defense capabilities.
A critical area of convergence between Seoul and Washington is the defense industrial sector, particularly naval shipbuilding. “As a powerhouse of the world’s shipbuilding industry, Korea has a great potential to support U.S efforts to revitalize naval power,” Kim said. That could entail providing maintenance or codeveloping U.S. Navy vessels.
The ROK and the U.S. are pursuing a comprehensive strategic alliance that combines security, economics and innovation, according to the Hudson Institute, a Washington, D.C.-based think tank. During a visit to Washington in August 2025, Lee pledged $350 billion in investment and $100 billion in liquefied natural gas purchases. South Korean firms committed an additional $150 billion.
Kim said the ROK increasingly supports regional stability by participating in multinational military exercises such as Talisman Sabre and Pitch Black, both in Australia. Such engagements demonstrate Seoul’s extended naval and aerial power, its growing interoperability with Allies and Partners, and its capacity to contribute to noncombat missions in the Indo-Pacific.
