For decades, American defence planners have viewed this chain of islands as strategically important because it forms a natural barrier separating the western Pacific from China’s coastal waters. Rather than relying solely on the deployment of additional American military forces, he stressed that effective deterrence depends on stronger regional defence capabilities among US allies. Manila has also strengthened defence cooperation with several other partners, including Japan and Australia, as concerns about maritime security continue to grow. Defence analysts say this approach reflects both the growing complexity of regional security challenges and the increasing military capabilities of US allies. His Southeast Asian tour is expected to include discussions on defence cooperation, military modernisation, regional deterrence and broader security challenges facing the Indo-Pacific.