How Japan Is Viewing the North Korea-Russia Alliance

Russian President Vladimir Putin’s new defense partnership with North Korea could have considerable consequences for global security, including potentially changing the military balance in Northeast Asia. For Japan, the geopolitical chessboard is rapidly becoming much more complicated.

A More Dangerous North Korea

Three dimensions of Putin’s recent visit to Asia—particularly his new defense agreement with North Korean leader Kim Jong Un—have implications for Japan’s choices ahead. The first, and most obvious, is the immediate effect of the Russia-North Korea axis on Japan’s strategic planners. Putin’s offer to deliver sophisticated precision weapons would give Pyongyang an added lethal edge on the Korean peninsula. Their joint statement coming out of the visit also declared that Russia will join in a potential fight if North Korea was attacked, creating a scenario in which two nuclear powers, China and Russia, could aid a belligerent North Korea.

But the more worrying prospect for Tokyo would be Moscow giving North Korean leader Kim Jong Un even more technological aid to bolster his country’s missile and nuclear programs. Missiles have always been Japan’s top concern. Pyongyang’s testing of medium- and long-range missiles has demonstrated that Kim wants to put Japan—and the U.S. military bases there—within reach.

A second dimension that’s worrying for Japan is the potential cooperation on intercontinental ballistic missiles (ICBMs). In December 2023, Pyongyang successfully launched an ICBM, believed to be a solid-fueled Hwasong-18. Japanese and South Korean defense authorities described the missile as being capable of reaching the United States. Moscow’s help with Pyongyang’s ballistic missile technology, including providing the satellites necessary to support it, would allow Kim to threaten retaliation against the American mainland should U.S. forces attack North Korea. A reliable, nuclear-capable North Korean ICBM, in other words, would raise the risk of “decoupling” the United States from its northeast Asian allies.

Russia’s Nuclear Shadow

Putin’s penchant for threatening to use nuclear weapons also complicates Japan’s security strategy. He has threatened escalation in Ukraine, both horizontally—to take the war to neighboring North Atlantic Treaty Organization (NATO) countries—as well as vertically—to use weapons of mass destruction on the battlefield. Japan would be highly vulnerable to nuclear coercion in the event of a crisis or conflict on the Korean peninsula.

The details of the “strategic comprehensive partnership agreement” announced by Putin and Kim have yet to be released publicly, but Russia’s offer of defense assistance to North Korea could include nuclear deterrence. Whereas China has historically been cautious when promising military aid to North Korea, Russia seems far less constrained.

Meanwhile, Japan and South Korea are seeking to bolster U.S. extended deterrence. Tokyo has announced that it will introduce conventional long-range missiles to its own deterrent posture, in addition to taking steps to integrate operational planning between U.S. and Japanese forces. Seoul and Washington issued the Washington Declaration in April 2023, a detailed restatement of the U.S. promise to use all means possible to defend South Korea.

Putin’s defense commitment to Kim could be responding to these upgrades in the U.S.-Japan and U.S.-South Korea alliances, or he could simply be continuing to pursue his goal of creating uncertainty about the nuclear threshold. For Japan and South Korea, two northeast Asian powers without nuclear weapons, this uncertainty over Russian intentions raises new questions about how to implement the U.S. nuclear umbrella.

More Complexity in the Indo-Pacific

A second consequence of Putin’s diplomacy in Asia is that it complicates Japan’s Free and Open Indo-Pacific strategy, and its successful effort along with the United States, Australia, and India to cooperate in countering Chinese efforts to upend the status quo. If Russia plans to team up with China in the region, this will only add to Japan’s diplomatic burden.

Japanese Prime Minister Kishida Fumio argues that Russia’s aggression against Ukraine cannot be seen solely as Europe’s problem but ought to be viewed as a challenge to the global order. Japan has been a conspicuous supporter of Ukraine; at the recent peace conference for Ukraine in Switzerland, Kishida announced a new ten-year plan offering security assistance to Kyiv, bringing its total commitments since March of 2022 to more than $12 billion. Putin could now be intimating that if the Indo-Pacific powers, Japan first and foremost among them, want to meddle in Europe, then he can reciprocate in the Indo-Pacific.

Of course, Russia has far less influence across the Indo-Pacific than Japan has in Europe. But Japan’s sanctions on Russia with the Group of Seven (G7) led Moscow to designate it as an “unfriendly nation” and to sanction Japanese policymakers and private sector citizens alike. Moreover, Russian military activities (some involving China) around Japan’s northern waters have increased, signaling that their territorial dispute will remain unresolved. Japan will need to pay close attention to both its northern and southern defenses.

Kishida’s New Headache

Japan’s prime minister has his own agenda with North Korea, one that seems increasingly thwarted by recent events. Japan’s conservatives have promised they would resolve the abductee issue: early this year, Kishida announced he would seek direct talks with Kim to bring Japanese captives being held in North Korea home again. This May, a South Korean newspaper reported a meeting between North Korean and Japanese officials on the matter, but the Japanese government refused to confirm it.

Putin’s visit to Asia throws a new wrench into Kishida’s plans. Japan has to do even more to cope with the rapid changes underway in its region. Kishida announced a massive upgrade in Japan’s defense spending in December 2022, but the declining value of the yen and the sticky politics of trying to persuade Japanese taxpayers to foot more of the bill have made it difficult for him to realize his goal.

One of Putin’s aims could also be to weaken coalition diplomacy among Indo-Pacific allies. Alongside the United States, Japan has invested deeply in this strategy, including the newly activated Quadrilateral Security Dialogue (or Quad) and NATO’s effort to strengthen ties with the Asia Pacific Four. Kishida has welcomed Europeans to the task of ensuring peace in the Indo-Pacific, and as the July NATO Summit will reveal, advocates that Indo-Pacific partners can do the same for Europe.

A Tighter Trio

Putin’s effort to rattle Northeast Asia should invite a direct response by the United States, Japan, and South Korea. This is the moment for the trilateral group to demonstrate their shared strategic purpose outlined at Camp David last year. Seoul and Tokyo need to bolster their restored military ties to cope with the new Russian commitment to enhancing North Korean capabilities. The arrival this past weekend of the USS Theodore Roosevelt strike group in Busan, South Korea, for trilateral military exercises is an important first step.  

The Kim-Putin meeting also underscores the need for the United States, Japan, and South Korea to consider how they would respond to simultaneous crises in Northeast Asia. Kishida’s point that what happened in Ukraine could easily happen in the Indo-Pacific was based on rising tensions across the Taiwan Strait. Taiwan and the Korean peninsula are simultaneously attracting major power challenges from China and Russia, respectively.

Given its geography, Japan has to consider this in its defense planning and integrate crisis management planning with both Washington and Seoul. A future conflict between the United States and China could be even more dangerous for Japan and South Korea if North Korea and Russia seize on the crisis as an opportunity. Putin could be unable to recast the balance of power in East Asia, but he is making it clear that Moscow’s and Pyongyang’s calculations in a crisis, in addition to Beijing’s, cannot be ignored. This is, in fact, Japan’s worst nightmare, and it could be for the United States as well.