Following a February meeting between Japan’s Prime Minister, who assumed office in September, and U.S. President Donald Trump, the two leaders released a statement expressing their commitment to “a new golden age” in U.S.-Japan relations.
The statement emphasized collaboration on economic growth, security, and space. However, subsequent actions by Trump, including measures impacting Japan, cast doubt on this cooperative commitment.
However, there may be a path for the two nations to reignite their pursuit of this golden era.
According to a report this week in the Japanese financial publication Nikkei, Japan is “exploring support” for Trump’s “Golden Dome” project. This ambitious missile defense system, inspired by Israel’s Iron Dome, would involve a network of satellites, sensors, and interceptors designed to defend the U.S. mainland from aerial attacks. Trump has stated that this system, estimated to cost hundreds of billions or even trillions of dollars, will be operational by the end of his term in 2029.
The report surfaced after Trump and Ishiba held a phone conversation last month where they “” and “engaged in a productive discussion aimed at furthering cooperation between Japan and the U.S. across various domains, including foreign policy, security, and the economy.”
In a statement following the second phone call on May 29, Ishiba refrained from detailing his conversation with Trump, but noted that “we had a truly candid exchange of views that resulted in each of us further deepening our understanding of the other’s stance. I intend to continue to work together with President Trump to further reinforce the Japan-U.S. alliance and our cooperative relationship, as well as to deepen our relations, through which will be able to play a greater role in fostering world peace, stability, and prosperity.”
Here’s what to know.
What Japan has to offer
In response to increasing regional threats, Japan has been increasing its national security investments. In December 2022, the country revealed its most significant military expansion since World War II, elevating its defense budget to the third-largest globally, trailing only the U.S. and China.
Concurrently, the world’s third-largest economy has encountered a need to prioritize areas such as AI, robotics, and , all critical for defense.
In its , Japan has allocated approximately $6 billion towards a system that features long-range missiles and a satellite network.
Tokyo has also intensified its collaboration with Washington, its only formal treaty ally, pledging over $3 billion this year for purchasing missile interceptors and a mobile reconnaissance radar for Okinawa, which is home to many U.S. military bases.
As Japan prioritizes space surveillance and security—planning to launch its first “space domain awareness” satellite in fiscal year 2026—the U.S. Space Force, responsible for the development of Trump’s “Golden Dome,” has recognized the country as one of its “.”
“I believe what you see from the United States is a recognition that throughout our history, we don’t go it alone when deterring conflict,” U.S. Space Force Lt. Gen. David N. Miller Jr. stated during a February visit to Japan. “We have found willing and abiding partnerships as fundamental to our ability to deter and ultimately, if necessary, defeat threats and deal with any crises that evolves.”
Steve Jordan Tomaszewski, vice president of space systems at the Aerospace Industries Association, suggested at a Center for Strategic and International Studies event in April that the U.S. and Japan should cooperate on missile warning and defense, as reported by National Defense magazine. “Golden Dome could be a golden opportunity for collaboration at the end of the day.”
What Japan has to gain
The foundation of cooperation between the two nations extends beyond defense. According to a report by the Stimson Center, a nonpartisan think-tank in Washington, “Economic security is another area that has become increasingly important in the U.S.-Japan alliance.”
While collaboration on Trump’s “Golden Dome” may provide some security assurances to Japan, given its proximity to potential adversaries like North Korea, China, and Russia—all of which have , according to the Nikkei report, Japan might leverage its participation in the project as leverage in trade negotiations.
Japan, heavily reliant on imports and exports, has urged Trump to reduce or eliminate tariffs on the country, including a 25% tariff on automotive parts and a 24% “” tariff, to 10%. According to , the Trump Administration has requested countries to submit their best offers in negotiations concerning these tariffs by Wednesday, June 4.
Following his recent call with Trump, Ishiba reiterated Japan’s unwavering stance on tariffs: “The Japanese side has consistently advocated for ‘investment rather than tariffs’ all along. By making investments in the U.S., we will generate employment in the United States while also leveraging Japan-U.S. cooperation to create better products. Japan’s calls to make what can be called a ‘win-win’ relationship have not changed in the slightest.”
