The perennially tense relationship between Tokyo and Moscow has taken a significant turn for the worse in recent months and Asia-Pacific strategists should assess the relevant dangers.

On October 19, ten Russian and Chinese warships passed through the Tsugaru Strait, a relatively narrow sea passage separating the main Japanese islands of Hokkaido and Honshu.

While the passage was not illegal, since the course was in designated international waters, the show of force serves as an unambiguous reminder to the Japanese that they have powerful, not especially friendly neighbors with their own agendas concerning the regional and global order.

Moscow has indicated its displeasure with both the AUKUS submarine deal, as well as the evident inclination of NATO to become more involved in Asia-Pacific security issues.

When Japanese Prime Minister Fumio Kishida said on November 10 that Japan would deal firmly with both China and also Russia, therefore, this was not terribly surprising.

Russia-Japan relations have been in steady decline for over a year. A visit by Russian Prime Minister Mikhail Mishustin to the contested Kurile Islands during July 2021 accentuated this trend. In addition, Moscow has taken steps to increase its fortifications on the contested islands.

So what is going on? Japan-Russia ties have formed a distinct anomaly in Northeast Asia for at least the last two decades.

Above all, it was then-prime minister Shinzo Abe who kept Russia-Japan relations moving in a positive direction. Altogether, Abe and Putin met 27 times, an extraordinary record of persistent dialogue.

Abe boldly overruled the explicit objection of US President Barack Obama and went to Russia to meet with Putin in May 2016, helping break Russia’s international isolation following the acute Ukraine crisis in 2014-15.

Abe could not quite pull off the breakthrough with Russia over the fraught island dispute.  However, their cordial and intensive relationship enabled noteworthy economic and cultural achievements.

A considerable side benefit, moreover, was to help dampen tensions on the neighboring Korean Peninsula during the exceedingly volatile period of 2017-18.

Japanese nationalists, seeking the return of Iturup and Kunashir to the north of Hokkaido, have long been critical of Abe’s overtures to Putin. Moreover, Russia has seemingly shut the door on any territorial concession with the constitutional revision of 2020.

Yet, these critics may have failed to see the larger stakes that Abe had been pursuing, namely the very future of the Asia-Pacific. In the absence of Abe, the critical Japan-Russia relationship seems to be left twisting in the wind – a situation that is plainly advantageous to China.

On October 26, a Russian paper, [Military Review], ran a story under the headline, “… Japan Is off the Leash.” The article begins: “Perhaps, in the light of recent events, it is time to talk about our peculiar neighbor, with whom we have not yet signed a peace treaty, that is, we are almost at war.”

The article also notes that Japan is the only country in the world that has a constitution prohibiting it from having an army and a navy.

Coming out about the time of the first joint Russia-China fleet patrol into the North Pacific via the Tsugaru Strait, the article seems to correspond to a new and disturbing pattern settling upon Northeast Asia. Moreover, a third China-Russia strategic aviation exercise is likely also in the offing.

As China’s influence in Moscow grows rapidly, Japanese strategists may be forced to contemplate some rather dark scenarios, including the dreaded “two front war” – simultaneous threats from both north and south.

Indeed, a rather troubling possibility these days is a Taiwan scenario in which Russia effectively neutralizes Japan by suddenly developing an aggressive posture in and around Hokkaido.

To prevent such a dangerous situation from developing, Tokyo should continue to woo Moscow, pursuing the tradition laid down by Abe that prioritizes commercial interdependence (the Eight-Point Cooperation Plan) over an unlikely territorial deal.

Two promising vectors for Russia-Japan coordination are North Korea and also the Arctic. Since it is abundantly clear that North Korea will not denuclearize, Japan and Russia should now coordinate and use their own niche capabilities to help gradually ease Pyongyang’s re-integration into the wider Northeast Asian community.

Meanwhile, the Northern Sea Route to Europe through the Arctic would clearly benefit Japanese shippers, and Russia would no doubt appreciate additional support.

Instead of playing symbolic games with NATO countries, Tokyo would be wise to focus on improving its rapidly declining relationship with Moscow, before it’s too late.

Lyle J. Goldstein is Director of Asia Engagement at Defense Priorities.

Vitaly Kozyrev is Professor of Political Science at Endicott College and Associate in Research at the Fairbank Center for Chinese Studies at Harvard University.