When Japanese Prime Minister Sanae Takaichi used her first Oval Office summit with Donald Trump to ask why the United States had not consulted its closest ally in Asia before attacking Iran, the US president responded with a reference to the Japanese attack on Pearl Harbor. Japanese officials present at the meeting scrambled to brush off the exchange, but many in Tokyo described it as excruciating.

The episode, recounted by the Financial Times in "The country that can't say no to Trump", captured the new mood of a relationship Japanese officials had long considered sacrosanct, "Hvylya" reports. Joshua Walker, president of the Japan Society, told the paper that "soft-power Japan is having to adapt very quickly to life in a hard-power world and, in terms of the alliance, in a very different set-up than the one it thought it was in."

Trump also goaded Takaichi during the summit about Japan's reliance on the Middle East for 90 percent of its oil, a vulnerability that made Tokyo's exclusion from the Iran decision-making all the more jarring. The prime minister, aware that the president had already begun taunting Britain for its refusal to commit militarily to the Iran campaign, had to convince Trump that Japan's US-written constitution prevented it from participating.

Takaichi's approach relied on what one US diplomat called "weapons-grade flattery and strategic transactionalism." She opened her meeting by telling the president, "It is only you, Donald, who can achieve peace across the world," and pledged tens of billions in fresh Japanese investment commitments in US-based projects. The tactics worked, at least temporarily. Trump did not demand that Japan break its constitutional constraints and send military support to the Strait of Hormuz, and he did not raise the dreaded question of Tokyo paying a larger share of the cost of stationing US forces in Japan.

The reprieve was short-lived. At a press conference on Monday, Trump listed the allies he had expected to join the war in Iran but which had not, naming Nato, Australia and South Korea, before adding the country that has long aspired to be America's most loyal friend. "You know who else didn't help us? Japan," the president said, pointedly noting that 50,000 US troops are currently stationed across the Japanese archipelago.

The contrast with the silence Washington offered Takaichi during a separate diplomatic crisis was stark. In October, after the prime minister acknowledged that Japan would become militarily embroiled if China attacked Taiwan, Beijing launched a diplomatic broadside against Tokyo that has yet to cease. Trump and his team said nothing in her defense, beyond a belated social media post by the US ambassador in Tokyo. "Hvylya" has previously detailed retired general Stanley McChrystal's argument that Trump's "America First" approach has gutted the alliance architecture Washington spent decades building.