Japan’s Northern Territories Dispute Explained for 2026

JAPAN · ANALYSIS

Japan’s Northern Territories dispute keeps Tokyo and Moscow without a formal peace treaty 80 years after the Second World War. For readers in the United States, the stalemate is no longer a historical footnote: it now shapes alliance credibility, Russian military posture and Pacific supply-chain risk.

Japan is a major U.S. ally in Asia. This analysis explains the island dispute behind the missing peace treaty, the actors, the business stakes and the scenarios that could change the North Pacific.

It draws on the Asia Intelligence Brief and official Japanese and Russian positions.

The Four Islands and the Missing Peace Treaty

Japan and Russia restored diplomatic relations in 1956 but never signed a peace treaty to formally end the Second World War. The reason is a disagreement over four territories at the southern end of the Kuril chain: Etorofu, Kunashiri, Shikotan and the Habomai Islands.

Japan calls these the Northern Territories and says they are inherent Japanese land under illegal Russian occupation. Russia administers them as part of Sakhalin Oblast and treats the postwar transfer as settled.

The islands sit between Hokkaido and Russia’s Kamchatka–Sakhalin region. They control approaches between the Pacific Ocean and the Sea of Okhotsk, which gives them military value far beyond their small population.

Soviet forces occupied the four islands between 28 August and 5 September 1945, in the final days of the war. Japan surrendered on 2 September 1945, but Tokyo has never accepted that sovereignty was lawfully transferred.

The 1951 San Francisco Peace Treaty complicated the matter. Japan renounced its claim to the Kuril Islands, but the treaty did not say which state would receive them, and the Soviet Union did not sign it.

Cape Nosappu in Nemuro, on Hokkaido’s eastern coast. Photo: Douglas P. Perkins / Wikimedia Commons, CC BY 3.0.

The 1956 Declaration and the Two-Island Problem

The central legal document is the Japan-Soviet Joint Declaration, signed in Moscow on 19 October 1956. Article 9 said the Soviet Union would hand over Habomai and Shikotan to Japan after a peace treaty was concluded.

The declaration ended the state of war and restored diplomatic relations. It did not settle Etorofu and Kunashiri, the two largest islands.

Japan’s Foreign Ministry calls the declaration a legally binding treaty that remains valid. Moscow has at times questioned whether even the 1956 promise remains operative under current conditions.

The structural dilemma is simple. Japan wants all four islands before a final peace treaty, while Russia has offered at most two, and only under conditions Tokyo has never accepted.

Since Russia’s full-scale invasion of Ukraine in February 2022, Moscow has suspended peace-treaty negotiations, ended visa-free visits for former Japanese residents and withdrawn from joint economic activities. Japan joined Western sanctions, and Russia classified Japan as an unfriendly state.

Recent Russian Military Moves

Moscow presents these measures as ordinary defence of sovereign territory. Japan calls them unacceptable and evidence that the occupation is being consolidated.

The military significance is strategic. The Kuril chain forms a barrier between the North Pacific and the Sea of Okhotsk, where Russia operates ballistic-missile submarines.

On 13 August 2026, President Vladimir Putin visited Etorofu. Foreign Minister Toshimitsu Motegi summoned Russian Ambassador Nikolay Nozdrev and lodged a strong protest.

Motegi said Japan’s policy of resolving the four-island attribution and concluding a peace treaty remains unchanged. The visit showed that Moscow sees no diplomatic cost in reinforcing its claim.

The Actors and What Each Wants

Prime Minister Sanae Takaichi leads Japan’s government and has called the dispute unresolved 80 years after the war.

President Vladimir Putin leads Russia and treats the islands as settled Russian territory. His government has used the dispute to signal that Moscow will not trade sovereignty for better relations.

Washington’s backing matters because the dispute tests the credibility of the US-Japan alliance and the principle that territory should not change hands by force.

China is not a direct party but has an interest in the dispute. Beijing has its own maritime conflicts with Japan, including the Senkaku Islands, and benefits when Japanese attention and resources are stretched.

Hokkaido Governor Naomichi Suzuki represents Hokkaido, the prefecture most directly connected to the islands. Local governments in Hokkaido run public-awareness campaigns and support former residents.

Economic and Business Stakes

The islands themselves have limited commercial output, but the dispute blocks normal Japanese-Russian economic cooperation in fisheries, energy and logistics. Japan and Russia had explored joint economic activities on the islands before 2022.

The wider business stakes concern the North Pacific. The waters around the islands are rich fishing grounds, and the straits are relevant to shipping and submarine cables.

For investors, the dispute adds a layer of political risk to Japanese equities with exposure to Hokkaido, fisheries and defence. Japanese defence spending has risen, and the Takaichi government has deepened security coordination with the United States.

The yen is not directly moved by the island dispute, but prolonged tension with Russia affects energy markets. Japan imports liquefied natural gas, and any disruption to North Pacific shipping lanes would raise costs.

A more militarised North Pacific could raise shipping insurance and freight costs on trans-Pacific routes.

What It Means for the United States

The dispute tests the US-Japan alliance in a specific way. The US-Japan security treaty applies to territories under Japan’s administration, and the Northern Territories are not administered by Japan.

A settlement that returned the islands to Japan would raise a new question: whether and how US forces could operate there. Russia would almost certainly demand restrictions on Japanese or American military use.

The dispute also feeds the Russia-China strategic relationship. A prolonged standoff keeps Japanese diplomatic attention divided and reinforces Russia’s military position in the western Pacific.

For Washington, the islands are part of a broader problem. Russia is a nuclear-armed Pacific power, China is expanding its naval reach, and Japan is increasing defence spending and coordination with the United States, Australia and South Korea.

That support is a signal to allies that Washington will not accept territorial change by force, even when the territory is small and remote.

What It Means for Latin America

Latin America is not a direct party, but the dispute affects the Pacific security environment in which the region trades.

A more militarised North Pacific raises the risk of incidents that could disrupt trans-Pacific logistics. Insurance costs and freight rates are sensitive to perceived security risk.

The dispute also reinforces a global pattern: territorial conflicts are being managed through military presence rather than negotiation. That pattern has parallels in other regions and encourages states to invest in deterrence.

For Latin American governments, the lesson is that frozen conflicts can remain stable for decades and then shift quickly. The Northern Territories have been disputed since 1945, but the Ukraine war changed the diplomatic calculus almost overnight.

The Scenarios

A postwar diplomatic reset is possible if a ceasefire or settlement in Ukraine creates room for Russia to seek sanctions relief. Moscow might revive the 1956 formula, but Japan would face pressure not to accept Habomai and Shikotan as the final settlement.

A two-plus-two compromise would involve Habomai and Shikotan with a separate arrangement for Etorofu and Kunashiri. That would face major obstacles, including Japan’s official four-island claim and Russian demands for security restrictions.

A dangerous scenario is miscalculation. Increased Russian military activity near Hokkaido raises the risk of an incident that neither side intends but that could escalate quickly.

What It Means for You

If you invest in Japanese equities, defence contractors or Asian supply chains, the Northern Territories dispute is a risk factor to monitor. It is not priced into most models, but it affects alliance politics and military planning.

If you work in shipping, logistics or commodities, the North Pacific is a critical corridor. Any incident near the Kuril chain could raise insurance and freight costs.

If you follow US foreign policy, the dispute is a test of whether Washington can support an ally without escalating a conflict with a nuclear-armed power. That test will shape the credibility of US security guarantees in Asia.

What Is Not Known

Access to the islands is governed by diplomatic arrangements rather than normal tourism rules.

It is not known whether Russia and Japan maintain any private diplomatic channel on the territorial question. Publicly, negotiations are suspended.

It is not known whether the United States has made any contingency plans for a hypothetical return of the islands to Japan. That question would become urgent only if a settlement became plausible.

What to Watch

Northern Territories Day on 7 February 2027 will be the next major public moment. Japan holds an annual national rally.

Russia announced military exercises in and around the South Kuril chain in August 2026. Moscow has used exercises to reinforce its sovereignty claim.

Watch for any change in Japan’s sanctions posture toward Russia. A shift would signal that Tokyo is creating diplomatic space for a future negotiation.

Watch for any resumption of grave visits or the Four-Island exchange programme. Their return would be an early sign of thaw.

Finally, watch for any US statement on the dispute. Any new formulation could indicate a shift in alliance planning.

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Frequently Asked Questions

What are the four islands in Japan’s Northern Territories dispute?

The four disputed territories are Etorofu, Kunashiri, Shikotan and the Habomai Islands. Japan calls them the Northern Territories, while Russia administers them as part of Sakhalin Oblast.

Why is there no peace treaty between Japan and Russia?

Japan and Russia have never signed a postwar peace treaty because they cannot agree on sovereignty over the four islands. Japan wants all four returned, while Russia treats its control as settled.

What did the 1956 Japan-Soviet Joint Declaration promise?

Article 9 of the 1956 declaration said the Soviet Union would hand over Habomai and Shikotan to Japan after a peace treaty was concluded. It did not settle Etorofu and Kunashiri.

Why does the dispute matter for the United States?

The dispute tests the credibility of the US-Japan alliance and the principle that territory should not change hands by force. It also affects military geography in the North Pacific, where Russia operates strategic submarines.

Has Russia increased its military presence on the islands?

Yes. Russia has expanded military infrastructure on the southern Kurils, particularly on Etorofu and Kunashiri.

Could the islands be returned to Japan?

A full return is unlikely while the Ukraine war continues and Russia’s relations with Japan remain adversarial. A two-island compromise is theoretically possible but faces major political obstacles in both countries.