“We see two trajectories in the Asia-Pacific [region] today,” Wang said. “One features efforts to advance solidarity, cooperation and economic integration. The other features attempts to stoke division and confrontation and revive the Cold War mentality.”

Seong-hyon Lee, a senior fellow at George H.W. Bush Foundation for US-China Relations, said by formalising the cooperation between the countries, the Camp David summit marked “a de facto military alliance without explicitly stating so”.

25:55

Biden is freezing out China’s tech industry

Biden is freezing out China’s tech industry

The trio also agreed to set up a new hotline to share military intelligence, pledged to share real-time data on North Korea’s missile launches and discussed measures to de-risk global supply chains from exposure to China.

Shi Yinhong, a professor of international affairs at Renmin University in Beijing, said although the summit fell short of announcing a military alliance, it marked a new stage of intensifying strategic coordination between Washington and China’s neighbours.

In recent years, he said, both the US and Japan had stepped up “extensive, in-depth and specific” preparations for a possible conflict with China over Taiwan, which Beijing sees as a runaway province that must be reunited, by force if necessary. He added both countries had also implemented supply chain restructuring to further squeeze China’s strategic and economic operating space.

“Under these circumstances, the establishment of a permanent military and economic security framework against China by the United States, Japan and South Korea was formally put on their joint agenda through effective coordination, and thus there was a Camp David meeting,” Shi said.

The latest Camp David deal is just more US-allied overkill

For Beijing, the most important takeaway from the summit was the high degree of coordination on China-related issues between the three powers, against the backdrop of the Biden administration’s “comprehensive suppression of China”, said Zhu Feng, a professor of international affairs at Nanjing University.

Of the three nations, Zhu said South Korea’s rapprochement with Japan and its change of heart on sensitive issues such as the South China Sea and Taiwan on Yoon’s watch were particularly unexpected for Beijing.

“While the US, Japan and South Korea have established a tighter trilateral alignment on regional security issues, the summit also meant that Seoul has basically ended its years-long policy of maintaining a balance between the US and China,” Zhu said.

“The fact that South Korea has effectively picked a side in the US-China rivalry will have a very important impact on China’s peripheral security and its strategic competition with the US in East Asia.”

Unlike Japan, South Korea used to be reluctant to side with the US on maritime disputes and cross-strait tensions. But since Yoon took office over a year ago, Seoul has sought closer military ties with Washington, improved strained ties with Tokyo and increasingly aligned itself with the two countries on China issues.

Beijing recently stepped up pressure on Seoul, publicly criticising the Yoon administration’s pro-US stance, particularly his pursuit of close security alignment with the US and Japan. In June, China’s ambassador to South Korea Xing Haiming was caught in a diplomatic row when he warned that Seoul would “definitely regret it” if it bet against Beijing in the US-China rivalry.

Apart from Yoon’s pivot towards the US, Zhu said China’s Wolf Warrior-diplomacy in dealing with South Korea, especially following Seoul’s deployment of a US missile defence system known as THAAD in 2016, had also had negative impacts on bilateral ties.

“Following Japan’s lead, South Korea has accepted that its security and strategic concerns trump other issues, including business and economic interests,” he said.

Benoit Hardy-Chartrand, an international affairs specialist at Temple University Japan in Tokyo, said Yoon’s election in South Korea was the key factor in bringing the three countries together.

“Without [Yoon’s] willingness to reach out to Japan despite the political risks it entailed, none of this would have been possible,” he said.

“This highlights the potential fragility of the trilateral partnership. While we cannot ignore the geopolitical variables that brought them together, this partnership remains liable to the vagaries of domestic politics in South Korea and, to a lesser extent, Japan.”

He noted that if a candidate from the progressive opposition, which is traditionally more anti-Japanese, won the 2027 presidential election in South Korea, it could “spell serious trouble for trilateral cooperation”.

Hardy-Chartrand added that the other factors behind the summit included North Korea’s repeated missile provocations, Russia’s invasion of Ukraine and a shared perception among regional countries of a growing challenge posed by China.

“We cannot understate how significant the Camp David summit was. Leaders often tend to overhype such diplomatic events in order to score domestic points, but in this case, bringing the three leaders together for the first Japan-South Korea-US stand-alone summit was not only a diplomatic success for Biden, but also a sign of the widening fractures in regional geopolitics,” he said.

Zhiqun Zhu, an international relations professor from Bucknell University in Pennsylvania, said the summit served to underline that the world was being divided into two Cold War-style camps, with the US and its allies on one side, and China, other authoritarian regimes and some developing countries on the other.

“As the Biden administration galvanises support from its allies in Europe and Asia in competing with China, tensions will not only grow between the US and China, but also between China and its Asian neighbours,” he said.

“As a result, East Asia will become more unstable, and the dangers of conflict in the Taiwan Strait and the South China Sea will increase.”

Zhu cautioned against what he called “a misguided belief” among the US and its allies that by strengthening security alliances, China would be deterred on issues such as Taiwan and the South China Sea.

Why US-Japan-South Korea cooperation should trouble China

“This miscalculation unfortunately underestimates China’s will and preparedness to defend what it considers ‘core’ national interests,” he said.

However, he said China should take a long view and wait for political changes in the US, South Korea and Japan before taking any action.

Lee pointed to a possible weakness of the partnership: the three leaders’ focus primarily on security “at a time when people are more concerned about the economy”.

“If these moves do not yield economic benefits, they risk facing domestic political backlash,” he said, adding that the leaders were trying to advance an economic partnership that complemented their security cooperation.

04:00

Brazil’s President Lula meets with Xi, seeks to expand trade, Chinese investments and talk Ukraine

Brazil’s President Lula meets with Xi, seeks to expand trade, Chinese investments and talk Ukraine

Kim Hyun-wook, a professor at Korea National Diplomatic Academy, also said domestic politics, especially leadership reshuffles, remained the biggest challenge for the trilateral partnership.

Kim also said that despite China’s frustration, it was unlikely to retaliate against Japan and South Korea due to economic difficulties and concerns about a public opinion backlash in both countries. He added that besides the North Korea factor, China’s hardline diplomacy with South Korea and Japan had also played a big role in pushing them into the arms of America.

“Beijing could until recently be comforted by the fact that South Korea was keen to maintain strong ties with China, in large part due to its economic dependence on its neighbour. But now that Seoul appears poised to move away from its traditional equidistance to Beijing and Washington, this is a blow to Chinese efforts to forge a favourable geopolitical environment and pry away American allies,” he said.

Additional reporting by Seong Hyeon Choi