Adam Liff, professor of East Asian international relations at Indiana University’s Hamilton Lugar School of Global and International Studies, part of the College of Arts and Sciences at Indiana University, published an analysis last month examining how the U.S.-Japan alliance has held up under the second Trump administration.
The piece, “The US-Japan Alliance under Trump 2.0: Still ‘Indispensable’ for America,” was published on July 9, 2026, by the Italian Institute for International Political Studies (ISPI), the Milan-based international affairs institute, as part of a new series assessing the state of the United States' alliances in Asia under Trump 2.0.
Liff writes that since Trump’s return to office Japan has retained its status in Washington as America’s most important partner in the Indo-Pacific, driven by close ties and shared interests in regional deterrence and secure supply chains, inter alia. President Trump has repeatedly joined his counterparts in Tokyo in calling for a “new Golden Age” of the U.S.-Japan alliance.
At the same time, Liff cautions that high-profile and celebratory summitry masks real anxieties in Tokyo and friction beneath the surface of the relationship. Even so, he concludes that Japan has weathered the unpredictability of Trump’s second term better than many of America’s other major treaty allies.
The analysis draws on Liff’s long-running research on Japanese foreign and security policy and the U.S.-Japan alliance, which he also advances as founding director of the Hamilton Lugar School’s 21st Century Japan Politics and Society Initiative (21JPSI). Students in the school’s East Asian Languages and Cultures department and International Studies program regularly engage with U.S.-Japan alliance-related topics through Liff’s courses on Japanese foreign policy and U.S. Asia-Pacific strategy, as well as through 21JPSI events and programming.
