Trump’s tariffs and unpredictability have rattled the region’s most dependable partnerships, forcing Japan and others to debate a more independent future.
During a state visit to the US in 2015 by Japan’s then Prime Minister Shinzo Abe, the enduring alliance between the two nations was on full display. At a White House dinner, President Barack Obama toasted Abe with sake from his home prefecture of Yamaguchi and attempted a haiku to celebrate their relationship. For his part, Abe invoked the Motown classic “Ain’t No Mountain High Enough” to capture Japan’s unwavering commitment to America.
The next day, as he became the first Japanese prime minister ever to address a joint meeting of Congress, Abe reflected on the decision to form an alliance with the US after Japan’s defeat in World War II. “That’s the path that made Japan grow and prosper,” he said, in a 43-minute speech punctuated by standing ovations. “Even today, there is no alternative.”
That view of the US as an irreplaceable partner has been held almost universally by Japanese policymakers for decades. It withstood 1980s battles over Japanese car imports, survived a 1987 submarine‐technology scandal and weathered Donald Trump’s first stint in the White House, with Abe navigating trade and military spending demands through skillful golf-course diplomacy.
But Trump’s far more capricious behavior in his second term, including hitting Japan with 15% tariffs, has taken a toll. While the levy is one of the better outcomes of Trump’s chaotic trade war, it’s far removed from the zero rate Japan argued for as a close ally and the largest foreign investor in the US. The lengthy and at times bad-tempered negotiations undermined current leader Shigeru Ishiba, who’s now fighting to keep his job after his ruling coalition lost control of Japan’s upper house in July elections.
Meanwhile, Trump’s handling of the Ukraine crisis has become a barometer of his ability to work with allies and put collective security interests ahead of his impulse to strike grand bargains.
Against this backdrop, there is a growing debate in Japan about the need for strategic independence. Even the once-taboo topic of atomic weapons has been raised by a fast-growing opposition party amid concerns about the reliability of the US nuclear umbrella.
Japan has long been the most dependable US ally in East Asia, a vital bulwark against China and a base from which the US military can project its power across the Pacific, including in any potential conflict over Taiwan. That such a debate is taking place shows the extent to which Trump has eroded US credibility in the region.
And if Japan wavers, other countries may not be far behind. There’s strong public support for acquiring nuclear weapons in South Korea — another key ally questioning Trump’s commitment after he tied US security guarantees to trade negotiations. Many in Australia are also questioning the wisdom of a multibillion-dollar agreement with the US and UK to develop a fleet of nuclear-powered submarines over 30 years. And while Philippine President Ferdinand Marcos Jr. has been staunchly in the US camp, allowing the Americans access to several military bases near Taiwan, his opponents are far more skeptical of Washington and may retake power in three years.
For some foreign policy experts, the idea that US alliances in Asia are at risk of unravelling is overblown. Japan has pledged to deepen military ties with the US through more extensive exercises and plans for a new joint military headquarters near Tokyo. And South Korea’s new president has spoken about the importance of the alliance ahead of his first visit to Washington this month.
“Rather than de-align, bandwagon with China, or pursue autarky through nuclear weapons, US allies are doubling down on integration with the United States,” wrote Michael Green, a former National Security Council official under President George W. Bush. He pointed to the new US military command center in Japan and more American access to military bases in the Philippines.
The darker view is that the Asia-Pacific region may be on the cusp of destabilizing change, as fraying US alliances raise the risk of conflict, geopolitical realignment and nuclear proliferation. “A withdrawal from even one major security treaty would send profound shockwaves through the region, creating ripple effects that would be difficult to predict or contain,” Syed Munir Khasru, chairman of The Institute for Policy, Advocacy, and Governance, wrote in May.
In September 1951, six years after the US bombings of Hiroshima and Nagasaki, the US and Japan signed a treaty that became the cornerstone of American security policy in the region. Inked at the US Sixth Army’s San Francisco headquarters, the agreement allowed American troops to remain on Japanese soil after the nation regained its sovereignty. At the signing ceremony with Secretary of State Dean Acheson, Prime Minister Shigeru Yoshida lamented that Japan was “utterly unprepared for self-defense.”
“We are very glad, therefore, that America, realizing that security of Japan means the security of the Pacific and of the world” has agreed to keep troops in the nation to “ward off the menace of Communist aggression,” Yoshida said.
The agreement was revised in 1960, giving the United States the right to establish bases in Japan in return for a commitment to defend the nation in the event of an attack. Today, some 53,000 American troops are stationed there, the US military’s largest permanent foreign deployment.
Since then, relations between Tokyo and Washington haven’t always been smooth sailing. One of the biggest strains came in the 1970s when President Richard Nixon announced he would visit China in a step toward normalizing relations. (The term “Nixon shock” encapsulated Japan’s grave concern at being blindsided by the planned visit.) The following decade, Japan’s rapid development led to fears it could challenge America’s economic dominance. In 1987, members of Congress smashed a Toshiba radio with sledgehammers outside the US Capitol after a subsidiary of Toshiba Corp. sold submarine technology to the Soviet Union.
But the security treaty has been an article of faith for the conservative Liberal Democratic Party, which has long dominated Japanese politics — and for Abe, the nation’s longest-serving prime minister, who was most recently in office from 2012 to 2020.
Amid growing threats from a nuclear-armed North Korea and an increasingly assertive China, Abe shifted Japan’s defense posture in part to reassure the US about its commitment to regional security. Despite large public protests, his government in 2014 broke with a post-war ban on Japan’s military using lethal force overseas and allowed it to defend allies coming under attack.
While Abe wanted to build a stronger military, he also knew that Japan would struggle to defend itself in any major confrontation with its highly militarized neighbors. The nightmare scenario for Japanese defense planners is a three-front conflict with China, North Korea and Russia. Abe knew the US alliance was essential.
Trump’s first term brought its own challenges: The president complained about an imbalanced relationship, calling out Japan’s trade surplus and demanding higher payments for the US troop presence. But as Trump and Abe’s friendship bloomed on the golf course, the pair signed a trade pact on some agricultural and industrial goods in 2019 that avoided targeting Japan’s all-important auto industry. And by the time a cost-sharing agreement for bases came up for renewal in 2022, Biden was president.
Trump revived his complaints about trade and the security treaty within months of starting his second term, which has undermined public faith in the alliance. In a national survey conducted by Japan’s Asahi newspaper in April, 77% of respondents said they didn’t think the US would defend Japan. A June survey from Pew Research Center found that 61% of Japanese had no confidence in Trump to do the right thing in world affairs; 55% of respondents had a favorable opinion of the US, down from 70% a year earlier.
Changing attitudes in Japan were reflected in the recent election, when Sanseito, a right-wing populist party that’s pushing a “Japanese First” agenda, saw a surge in support. The party is advocating a more muscular diplomatic stance and has opened a discussion on whether Japan should obtain nuclear weapons to defend itself.
The long shadow of Hiroshima and Nagasaki has for decades sidelined any such discussion. Nevertheless, Japan is considered a “nuclear threshold” state because it has large stores of fissile material that could be used to develop a bomb in a matter of months. While Sanseito finished second in the total number of votes, it secured only a handful of seats. But even a nascent debate over nuclear weapons marks a major shift for Japan.
Attitudes are also changing in the heart of the establishment, with Trump triggering rare displays of anger in the LDP. When the president sent a public letter in July informing Japan it would be subject to a 25% tariff rate, LDP policy chief Itsunori Onodera expressed “strong resentment” and said such unilateral action was rude. In an election stump speech, Prime Minister Ishiba said Japan would “not be disrespected” by the US.
Perhaps most surprisingly, Abe’s long-serving national security adviser, Shotaro Yachi, said in a recent newspaper interview that Tokyo should no longer continue to treat the alliance as a given. Japan should be able to walk away if necessary and even align with countries such as China on issues including trade, he said. Yachi added that the friction with the US was a lesson: Japan needs to be able to defend itself without relying on others.
Concerns about America’s reliability as a security partner were compounded in late February when Trump, aided by Vice President JD Vance, humiliated Ukrainian President Volodymyr Zelenskiy in the Oval Office, and then temporarily suspended intelligence-sharing and military aid. Unlike Japan, South Korea and Australia, Ukraine doesn’t have a security treaty with the US — but that didn’t lessen the shock among Asian allies.
“What Japan has learned from the Ukraine war is that the era where we could rely entirely on the US is over,” Nobukatsu Kanehara, who spent several years as Abe’s deputy national security adviser, told Japan’s Nikkei newspaper shortly after the Zelenskiy-Trump summit.
Like Japan, South Korea leans on the US for security, specifically to deter its northern neighbor. Some 28,500 American personnel are stationed in the country, and Camp Humphreys in Pyeongtaek is the largest US military base overseas. South Korean President Lee Jae Myung will meet with Trump in Washington on Aug. 25 for talks that will likely cover defense spending.
Australia got its own reality check in June, when the Trump administration said it was reviewing a Biden-era pact to develop nuclear-powered submarines with the nation and the UK. The 2021 deal would see the US sell Australia as many as five nuclear-powered Virginia-class submarines by the early 2030s, while a next-generation attack craft is developed. The Pentagon is now concerned the sale could degrade the capabilities of the US Navy amid its own procurement delays. A failure to acquire the submarines would blow a hole through Australia’s security at a time of rising tensions with China in the Indo-Pacific.
Such diplomatic friction has raised the question of what “Plan B” might look like for US allies in Asia. European nations are also worried about Trump’s commitment to the North Atlantic Treaty Organization. But even without the US, NATO members have considerable collective power to deter Russia. No such arrangement exists among democracies in the Asia-Pacific region. While joint military exercises and agreements to share supplies are becoming more common, the prospect of a regional mutual security guarantee remains remote. That’s mainly because the “hub and spoke” model of alliances — with the US as the hub and its allies as individual spokes — has long provided an adequate security guarantee.
Ishiba, a former defense minister, has said a regional security pact would bolster deterrence against potential aggressors. But long-held grievances would make reaching such an agreement challenging. For one, the idea of the Japanese military operating in South Korea remains deeply unpopular because of the nation’s harsh colonization of the Korean peninsula from 1910 to 1945.
The same problems exist elsewhere in Asia, where nearly every country has some sort of historical dispute with neighbors that perpetually leads to conflict. Back in the 1950s, the US and other western powers formed the Southeast Asia Treaty Organization as a regional NATO to fight communism. But it only included two nations in the region, the Philippines and Thailand, and competing interests meant other members including Pakistan often disagreed on when to intervene. It disbanded in 1977.
Another factor is the economic power of China, which has warned against the creation of an “Asian NATO.” Despite being the biggest security concern for many countries in the region, China is also a major trading partner and has shown it’s willing to use economic coercion against other countries — including throttling the export of rare earth minerals to the US during their ongoing trade dispute.
China now has the world’s largest navy by number of ships and its 2024 defense budget was more than twice the combined military spending of Japan, South Korea, Australia and the Philippines, according to the Stockholm International Peace Research Institute.
Over the past decade, Japan, South Korea, Australia and New Zealand have formed deeper security ties with NATO, and European navies are making more frequent appearances in the Asia-Pacific region. But the harsh reality is that the US is irreplaceable without an alternative collective security pact.
What seems likely is that Trump will continue to press allies to pay more for US military protection and to ramp up their own defense spending. US Defense Secretary Pete Hegseth has said American allies in Asia should follow the lead of NATO countries and commit to defense spending equivalent to 5% of gross domestic product — compared with 1.4% in Japan and 2.6% in South Korea at the end of last year. Japan faces a key test next year when negotiations are likely to start on a new five-year deal on cost-sharing for US bases.
Given Trump’s transactional approach to foreign policy and penchant for grand bargains, allies in Asia and beyond will no doubt remain unsettled and ponder alternatives to Pax Americana.
“The Trump madman theory, which postulates that his erratic behavior is a useful tactic to confuse adversaries, may apply to Beijing,” Green wrote. “But there is absolutely no advantage to chaos when it comes to managing alliances.”
Alastair Gale covers Japanese politics and Asian security for Bloomberg News and is based in Tokyo.