The US, South Korea and Japan have agreed to a new intelligence sharing arrangement that will deepen military cooperation between the three countries and raise the already fraught tensions in the region. It is the first such agreement involving Seoul and Tokyo, and follows the dropping of a more extensive bilateral deal in 2012 due to public opposition in South Korea.

The new agreement is officially limited in scope to sharing intelligence on North Korea and is a memorandum of understanding, rather than a legally binding treaty. Moreover, Japan and South Korea will not share intelligence directly, but rather will pass and receive it indirectly through the United States.

There was no formal joint signing ceremony. Instead, a US official had to fly to Tokyo and Seoul to obtain the signatures of the Japanese and South Korean defence ministers. Nothing was revealed publicly prior to a public announcement on December 29 that the agreement had gone into effect.

An unnamed South Korean defense ministry official told the Yonhap news agency that the agreement was not completely finalized. “Going forward, [the three countries] plan to have follow-up consultations to determine the level of information to be shared,” he said.

The agreement will ramp up pressure against North Korea under conditions where the US has deliberately provoked a confrontation with Pyongyang over unsubstantiated allegations that it hacked into Sony Pictures Entertainment. Supposedly the hacking was in retaliation for The Interview, a deliberately insulting movie, made in collaboration with the US intelligence establishment, depicting the fictitious assassination of North Korean leader Kim Jong-un. Pyongyang branded the new trilateral deal a “grave military provocation.”

The Obama administration has been pressing both allies for an intelligence sharing deal and closer trilateral military collaboration for some time. However, sharp disagreement between Tokyo and Seoul over a range of issues, including the Japanese government’s attempts to whitewash Japan’s war crimes in the region during the 1930s and 1940s, have been a barrier. Japanese Prime Minister Shinzo Abe and South Korean President Park Geun-hye have not held a joint summit since coming to office two years ago.

While the memorandum of understanding makes no direct mention of China, Beijing is clearly the target. Over the past five years, the Obama administration has engaged in a diplomatic offensive and military build-up throughout the region—the so-called “pivot to Asia”—aimed at undermining Beijing and preparing for war. The Pentagon regards close collaboration between Japan and South Korea, both of which have substantial US military bases, as essential to its war planning.

The claim that the trilateral deal is only aimed only against North Korea does not stand up to scrutiny. The failed bilateral agreement in 2012 would have allowed for sharing intelligence on China and is clearly what the US wants. The current memorandum of understanding is simply a stepping stone for wider collaboration.

Commenting on the trilateral deal, Robert Dujarric, the director of the Institute of Contemporary Asian Studies at Temple University’s Tokyo campus, said of South Korea and Japan, “We disagree on history, we disagree on [the disputed island] Dokdo, but we can work together and this is a message to North Korea and China.”

Beijing criticised the intelligence sharing agreement. Foreign ministry spokeswoman Hua Chunying commented, “We see that the situation on the Korean Peninsula is unstable. We hope that the sides will make more effort to strengthen mutual confidence and will not take actions destabilizing the situation.”

The US is also pushing for Japan and South Korea to collaborate in other areas. The latest deal will open the way for South Korea to take part in the joint US-Japanese anti-ballistic missile system that is already under construction in North East Asia. Intelligence sharing between the three countries would be essential to such a project.

Seoul has been cautious about backing the US anti-missile system, which is aimed principally at China and Russia. On top of China being South Korea’s largest trading partner, Seoul is also attempting to win Beijing’s support for its plans for the reunification of the Korean Peninsula. South Korea has just proposed talks in January on unification at the ministerial level and is undoubtedly hoping that China will apply pressure to North Korea to take part.

South Korea has proceeded with plans to develop its own indigenous anti-missile system known as the Korean Air and Missile Defense system. This has not prevented Defense Minister Han Min-gu and National Security Office chief Kim Kwan-jin from expressing their support earlier this year for the US to place a Thermal High Altitude Area Defense (THAAD) system in South Korea.

Despite the Park administration’s rhetoric about building a better relationship with China, it has worked in sync with the US “pivot.” Even the public differences with Tokyo have not dampened behind-the-scenes cooperation.

A conference in July hosted by the Pacific Forum, the Asia-Pacific wing of the Center for Strategic and International Studies (CSIS), was attended by officials, military officers, and policy experts from the US, Japan, and South Korea.

Brad Glosserman, the executive director of the Pacific Forum, noted, “To the credit of both South Korea and Japan, the difficulties [between the two countries] have been contained, with both governments insulating large elements of the security dialogue from the most divisive aspects of relations.” This had been achieved by “keeping cooperation under the radar.”

Among its other objectives, the latest US provocation against North Korea over the hacking of Sony will be exploited to justify trilateral collaboration on other fronts such as cyber espionage and cyber-warfare. The US appears to have already responded to Pyongyang’s alleged hacking by blacking out North Korea’s internet on at least two occasions over the past week.