Japan: An Indispensable Partner in the Indo-Pacific
This commentary is part of a report from the CSIS Geopolitics and Foreign Policy Department entitled The Global Impact of the 2024 U.S. Presidential Election. The report features a set of essays assessing the meaning of the election for Europe, Russia, Eurasia, the Indo-Pacific, the Americas, Africa, and the Middle East.
The U.S.-Japan security alliance is on a roll—and has been for several years across multiple administrations. Although strong during the Obama administration, the alliance deepened significantly under President Trump. In a rapidly deteriorating regional security environment, hardening U.S. policy toward China brought Washington into tighter alignment with Tokyo on the need to address Chinese revisionist behavior and strengthen deterrence. Japanese prime minister Abe Shinzo was notably successful at forging a close personal relationship with Trump, which helped Tokyo avoid the challenges other allies experienced during his administration, particularly his accusations that NATO and South Korea were free-riding on U.S. security guarantees. Under Trump, the United States embraced Japan as its partner of choice in Asia and even began to echo Abe’s strategic vision: pursuing a “free and open Indo-Pacific” to underwrite stability and prosperity in the world’s most dynamic region.
The trend accelerated under President Biden in partnership with Prime Minister Kishida Fumio. Japan embarked on a historic defense buildup, with plans to nearly double defense spending by 2027 and invest in new capabilities that will transform the Japan Self-Defense Forces into a more formidable military. Under Kishida, Tokyo embraced the philosophy that strengthening its defense capabilities was the best means of ensuring sustained U.S. commitment to the alliance with Japan. Diplomatically, the allies focused heavily on “minilateralism” in the region, building closer partnerships with South Korea, Australia, the Philippines, and India. Japan emerged as an important supporter of Ukraine and collaborated with the United States and other partners to champion global governance norms as the host of the 2023 G7 summit. Washington and Tokyo also collaborated closely on issues related to economic security and technology competition with China, including semiconductor export controls—though Tokyo, at times, has resisted Washington’s push to broaden the list of technologies and investments in China subject to restrictions. Today the U.S.-Japan alliance is at a moment of historic strength with a robust framework to tackle a range of economic and security challenges.
So how is Tokyo preparing for a possible return of Trump or a new Harris administration? Japan—which will have a new leader by the time of the U.S. presidential election—approaches the prospect of Trump 2.0 with some trepidation given Abe’s tragic assassination in July 2022. Abe was a leader uniquely adept at explaining to Trump how Japan’s strategic trajectory supports U.S. interests. Under a Trump administration, Japan would seek to sustain alignment on issues related to China while working to dampen Trump’s unilateral instincts on North Korea and encourage coordinated messaging toward Pyongyang. Trump’s resolve to double down on tariffs could complicate bilateral trade ties. Japan would likely point to its long history of foreign direct investment in the United States to further its credentials as an economic partner and work to find ways to sustain U.S. leadership on international economic matters—for example, countering Chinese economic coercion—assuming Washington continues to shun multilateral free trade agreements.
Japan’s role as the region’s second-largest economy and host to U.S. military capabilities critical for regional stability would likely mitigate the risk of a major alliance rupture. However, a looming host-nation support negotiation in 2026 (to reset Japan’s budget for hosting U.S. forces) and potential pressure to increase imports of U.S. defense equipment (for which Trump advocated during his presidency) could strain the relationship. Tokyo would hedge against the prospect of a more isolationist United States under Trump by investing more heavily in its regional relationships—particularly with Australia—while continuing to encourage regional networking with the United States and other partners under constructs such as the Quad, which was embraced by the first Trump administration and has been elevated to the leader level by Biden. Further, Japan would double down on its quest to strengthen its defense industry, in a bid to reduce reliance on the United States.
By contrast, Tokyo would approach a Harris administration with the expectation of broad continuity. However, it would watch closely to see if Harris sustains Biden’s hawkish approach to China, including on economic issues, and his focus on building closer partnerships in the Indo-Pacific. Japanese strategists would scrutinize U.S. defense spending for concrete evidence of a sustained commitment to regional security. Harris’s views on foreign policy remain a source of uncertainty in Tokyo, particularly trade policy. Japan was disappointed by Biden’s openness to tariffs and resistance to multilateral trade agreements, a continuation of Trump’s approach which Japanese interlocutors consider a debilitating weakness for U.S. strategy in the region. Kishida helped Biden unveil the Indo-Pacific Economic Framework for Prosperity (IPEF) in Tokyo to further U.S. economic engagement, but Japan and other IPEF members have privately criticized the initiative as a weak substitute for negotiations on access to the U.S. market—the priority for regional trade partners. Tokyo would likely encourage Harris to pursue a more forward-leaning approach to trade policy, though protectionist trade politics could diminish the prospects under either candidate, forcing Japan and other partners to shape economic rules and norms absent U.S. leadership.
Regardless of who is elected in November, Japan will remain an indispensable partner to the United States in the Indo-Pacific. No other U.S. ally provides the combination of strong strategic alignment and resources to shape regional geopolitics in favor of the existing rules-based order. Therefore, it is in U.S. interests to further bilateral ties with Tokyo and coordinate with other like-minded partners to preserve the centrality of the U.S. alliance network to regional stability and prosperity. The next U.S. president therefore should accomplish the following:
- Advance alliance integration. Kishida’s official visit to Washington in April 2024 yielded a shared commitment to upgrade alliance command and control structures that should strengthen operational links between the two militaries and bilateral coordination in the event of a contingency. The new U.S. president should signal an intent to advance this agenda, such as by requesting resources from Congress to fund it, and continue building a more operational bilateral military alliance. Relatedly, the next U.S. administration should sustain the recent momentum for defense industry cooperation to encourage joint capabilities that can leverage Japan’s industrial capacity and build a more resilient defense supply chain.
- Sustain the focus on networking habits of cooperation across the Indo-Pacific. Recent advances in U.S.-Japan cooperation with third-country partners, including South Korea, Australia, and the Philippines, underscore that China cannot drive a wedge between the United States and its allies. Other networks such as the Quad, which emphasizes providing public goods to developing countries, will prove vital to ensuring a stable and prosperous future for the Indo-Pacific region.
- Develop a more comprehensive approach to strategic competition. Chinese efforts to weaken support for the existing order by enhancing its influence in the developing world necessitate joint strategies among U.S. allies and partners to further an affirmative development agenda across the Indo-Pacific and beyond.
Christopher B. Johnstone is the former senior adviser and Japan Chair at the Center for Strategic and International Studies (CSIS) in Washington, D.C. Nicholas Szechenyi is the vice president of the Geopolitics and Foreign Policy Department and a senior fellow with the Japan Chair at CSIS.