From a shared commitment to crisis consultation to the "principles" of trilateral engagement, the outcomes from this week's landmark summit between South Korea, the United States and Japan are likely to put their once-fragile security cooperation on a more robust, sustainable, consistent footing, analysts said Saturday.

President Yoon Suk Yeol and his US and Japanese counterparts, Joe Biden and Fumio Kishida, adopted a series of documents committing each other to sturdier three-way cooperation during their historic summit at Camp David in Maryland on Friday, underscoring their deepening solidarity amid North Korea's saber-rattling, China's assertiveness and Russia's war in Ukraine.

The documents entailed agreements to consult with one another in the event of a common threat and hold three-way talks between the leaders, foreign ministers, defense ministers and national security advisers at least annually, as well as an intention to hold annual "multi-domain" military exercises on a regular basis.

They represented telltale signs of the three-way partnership being institutionalized as a thaw in the relations between Seoul and Tokyo -- long fraught with historical and territorial spats -- has created an opening for the three nations to close ranks and confront shared challenges.

"We made history with the first-ever standalone summit between the leaders of our three countries as well as our commitment to meet together on the leader level annually and to have all our relative Cabinet member people meet on a regular basis from this point on, not just this year, not next year, forever," Biden told reporters at Camp David, a place that he said symbolizes the "power of new beginnings and new possibilities."

"In the months and years ahead, we're going to continue to seize those possibilities together ... unwavering in our unity and unmatched in our resolve," he added.

Just years ago, the scene of the three leaders meeting trilaterally in a stand-alone setting with such a level of unity was seldom anticipated as historical grievances stemming from Japan's 1910-45 colonial rule of Korea have gotten in the way of attempts at deepening trilateral cooperation.

Even more so as tensions spilled over into economic and security domains as witnessed in export control rows between Seoul and Tokyo as well as a rancorous spat over low-altitude flybys by Japanese maritime patrol aircraft over South Korean warships in 2018 and 2019.

But the Yoon administration's decision in March to resolve the issue of Japan's wartime forced labor has given rise to a thaw in the bilateral ties, while North Korea's growing nuclear and missile threats have underscored the urgency for the two neighbors to patch things up.

In the midst of an intensifying Sino-US rivalry, Biden has been seen promoting rapprochement between Seoul and Tokyo, apparently harnessing his experience as vice president during the Barack Obama administration that helped foster a thaw between the neighbors as seen in a 2015 deal to address the issue of Japan's wartime sexual slavery.

A series of agreements contained in their summit documents marked a culmination of tripartite efforts to bring three-way cooperation to what officials have called a "new height."

Yoon, Biden and Kishida adopted the documents, titled the "Camp David Principles," the "Commitment to Consult," and the "Spirit of Camp David," to chart a future course of their cooperation on a sustainable and consistent basis as well as a wider range of areas, including defense, economic security and technology.

Their summit agreements also highlighted their tightening alignment on geopolitically sensitive issues, like those concerning the South China Sea -- a crucial waterway plagued by competing territorial claims -- and Taiwan, the self-governed democratic island that China claims as its territory.

On the North Korean front, the three leaders agreed to operationalize the real-time sharing of North Korean missile warning data by the end of this year, establish a new trilateral working group to combat North Korea's cyberthreats and block its cyber-enabled sanctions evasion, and hold annual multi-domain exercises regularly.

These agreements are bound to rile North Korea and China, but security uncertainties stemming from them have driven Seoul, Washington and Tokyo to such a level of cooperation short of what could amount to a formal collective defense mechanism, analysts said.

"The agreements highlight that three-way cooperation is being institutionalized to ensure that it would not swing or fluctuate due to a leadership change or other factors in each other's capital," Kim Yeol-su, a senior security expert at the Korea Institute for Military Affairs, said.

"With the countries' cooperation regularized among the leaders, foreign and defense ministers and national security advisers, it can gain greater sustainability, continuity and predictability," he added.

U.S. officials indicated that the Camp David summit agreements centered on efforts to "lock in" three-way engagement and make it difficult to "backtrack."

"Today, we are going to lay a strong foundation for this trilateral partnership to make sure that it's deep, it is strong and that it's built to last," U.S. National Security Adviser Jake Sullivan told reporters before the summit.

"We're opening a new era and we're making sure that era has staying power ... So that means regularizing meetings between our leaders and our senior officials on an annual basis to discuss the broad agenda of security technology, regional strategy, economic partnership and more," he added.

Despite such an upbeat assessment, there are still variables that could potentially hamper the implementation of summit agreements.

Nam Chang-hee, a professor of political science at Inha University, took note of possible "constraints," such as lingering historical tensions between South Korea and Japan, China's expected resistance to the closer-knit three-way partnership and US domestic politics, where there are undercurrents of isolationism.

"Still, it's a meaningful move towards optimized trilateral cooperation," Nam said.

The summit agreement on the "commitment to consult" in the event of a crisis added to the speculation that Seoul, Washington and Tokyo are on course to create a formal alliance, but officials have dismissed the notion.

"It is not a formal alliance commitment, it is not a collective defense commitment that is lifted from an early Cold War security treaty," a US administration official told reporters earlier this week. (Yonhap)