In US foreign policy circles, there has been a long coveted strategic aim in East Asia: the formation of a trilateral alliance with South Korea and Japan to present a united front against common security concerns, including China’s growing influence.

The only problem? South Korea and Japan just cannot seem to get along. Relations between Tokyo and Seoul, long strained by historical issues stemming from Japan’s 1910-45 colonisation of the Korean peninsula, have soured further as the sides stumble from one controversy to the next.

In recent weeks, the two sides have clashed over an encounter between their militaries in international waters, and the issues of Korean forced labourers and “comfort women” pressed into sexual slavery during the second world war.

“The United States has long hoped that its two allies in Asia would work more closely together, bilaterally and trilaterally, with the United States to address and combat regional security threats,” said Brad Glosserman, the deputy director of Tama University’s Centre for Rulemaking Strategies in Tokyo.

“There’s no opportunity for the system to snap back. It’s just one blow after another.”

On Wednesday, a South Korean court seized the assets of a Japanese company to compensate victims of forced labour, following a related Supreme Court decision that Taro Kono, Japan’s foreign minister, called “totally unacceptable”. In December, Tokyo accused a South Korean vessel of locking onto one of its patrol aircraft with its targeting radar, a preliminary step before firing at an enemy.

This prompted an angry denial from Seoul. In the weeks since, the rift has deepened, amid a public war of words over who was in the wrong.

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Simultaneously, the 2015 deal to settle the issue of “comfort women” was undermined in November when Seoul announced it would disband a compensation fund that formed the centrepiece of the agreement. The deal has been opposed by some survivors who argue it does not sufficiently assert Japan’s responsibility for its wartime abuses.

“The bottom line is that these two countries need each other and have diametrically opposed views in the function of their national identity,” Glosserman said, referring to the pair’s contrasting interpretations of history.

South Korea and Japan have plenty in common: both are democracies that host US troops and are broadly aligned with the US view of the “rules-based order” in Asia. More importantly, both governments see North Korea’s nuclear and missile programmes as a threat, and regard the prospect of Chinese hegemony in Asia with trepidation.

“When it comes to security issues in international politics, usually when there’s a common threat that is extremely acute, that’s when you can get two sides to partition or segment different issues,” said Andrew Yeo, an associate professor of politics and director of Asian Studies at the Catholic University of America.

In South Korea and Japan, however, domestic political pressures arising from a near-constant churn of historical and territorial controversies have prevented closer coordination.

Last year, the Asahi newspaper reported that Seoul was sharing little military intelligence with Tokyo despite the countries signing a related pact in 2016. That agreement provoked a public backlash in South Korea, where memories of Japanese colonisation remain raw. Around the same time, Seoul knocked back a US proposal for three-way military drills involving Tokyo.

Nonetheless, Washington has expended diplomatic energy for years trying to bring the sides closer together to address what it regards as common challenges.

“The US has done a great deal of work, but quietly, in ways that would antagonise neither side and be able to allow them to accuse Washington of taking sides in the dispute,” Glosserman said.

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During his presidency in 2014, Barack Obama brought former South Korean president Park Geun-hye and Japanese Prime Minister Shinzo Abe together for their first face-to-face talks at the Nuclear Security Summit in The Hague. Obama later hailed the meeting as an example of the common cause between the three countries when it came to North Korea and other challenges.

Since then, President Donald Trump has distanced himself from US alliances abroad, preferring an “America First” mantra and a sharper focus on problems at home. Yet it seems that Washington’s longer-term objective is still for Japan and South Korea to put aside their differences and cooperate on shared strategic goals.

“The logical thing is it seems like they should be closely aligned,” Yeo said. “I am optimistic in the long run that these differences, even if they cannot be resolved, can be managed so that you can have all three countries working together to address security issues in East Asia.”