Russia and Japan have yet to sign a formal peace treaty to end World War II. Both nations’ reluctance boils down to their dispute over a string of islands stretching from Hokkaido, Japan’s northernmost island, to the southern tip of Russia’s Kamchatka Peninsula. This archipelago—known in both the Western and Russian vernacular as the Kuril Islands—separates the Sea of Okhotsk from the North Pacific Ocean. The islands not only border rich fishing grounds, but also boast an abundance of hot springs, minerals, and rare earth metals critical to the production of supersonic aircrafts.
Russia and Japan’s dispute over the Kuril Islands dates back to the nineteenth century, but the current disagreement specifically centers around the South Kuril Islands, known to the Japanese as the “Northern Territories.” In Japan’s view, Russia is illegally occupying its Northern Territories; Russia, on the other hand, purports that the Kuril Islands are rightfully Russia’s following Japan’s surrender in World War II. The rest of the world must consider the ramifications of Russia’s recent militarization of the Kuril Islands, with nations like China, the United States, and Ukraine now deciding whether or not to get involved in the dispute.
Russia’s control of these islands since 1945 has granted the nation access to the Pacific Ocean and, therefore, the US West Coast. Recently, Russia has capitalized on the strategic location of the Kuril Islands by militarizing the archipelago. Since 2015, it has constructed missile systems, permanently deployed anti-air missile launchers, and built more than 50 new pieces of military infrastructure. This rapid militarization of the Kuril Islands has not gained lots of media attention due to Russia’s invasion of Ukraine.
An Overview of Russo-Japanese Relations Regarding the Kuril Islands
The dispute for the Kuril Islands dates back to the 1855 Treaty of Shimoda. Through the treaty, the Russian Empire gained control of the entire archipelago, with the exception of the four southernmost islands, which went to Japan. Twenty years later, the Russian Empire signed the 1875 Treaty of Saint Petersburg to address Russo-Japanese conflicts in Sakhalin—a large island north of the four Kuril Islands that had been co-occupied by Russia and Japan since 1855—and ceded Russian ownership of the entire Kuril Island chain to Japan, in exchange for the Southern Sakhalin Island, which Russia possesses to this day. Then, with the 1905 Portsmouth Peace Treaty following Japan’s victory in the Russo-Japanese War, Japan retained the Kuril Islands and regained control of the Southern Sakhalin Island. With this treaty, Japan cemented its position as the greatest power in Northeast Asia. Japan maintained this status until the end of World War II.
Questions surrounding Japanese sovereignty over the Kuril Islands first arose in 1943 during the Cairo and Tehran Conferences, in which the Allies met to formulate strategies to attack Japan and Germany during World War II. Though the Soviet Union did not attend the Cairo Conference, the Allied Powers declared that “Japan [would] be expelled from all the territories which she has taken by violence and greed.” During the Tehran Conference, which the Soviet Union attended, US President Franklin Delano Roosevelt recommended that the Southern Sakhalin Island and Kuril Islands be returned to the Soviet Union; however, he also recommended that the Japanese retain fishing rights in the Northern Kuril Islands, that the Southern Kuril Islands remain in Japanese possession, and that they be disarmed like the rest of the Japanese Empire. These conferences yielded solely recommendations—nothing with legal standing arose from them.
The 1945 Yalta Agreement, which resulted from a meeting among the Allies to negotiate the USSR’s entry into the war against Japan, prompted the Soviet occupation of the Kuril Islands. Though President Roosevelt agreed that the Soviet Union should gain possession of the archipelago, his signature on the Yalta Agreement still did not legally cede the territory. Washington officials have denied that the United States had the authority to authorize such a transfer; rather, the agreement formalized US consent to the Soviets’ wish to negotiate directly with Japan for the transfer of the Kuril Islands. The agreement, regarding the Soviets gaining possession of the archipelago, did not include the word “all” before “Kurils.” Six years later, the Allies and Japan signed the 1951 San Francisco Peace Treaty, which forced Japan to give up its claim to the Kurils; however, the treaty still did not recognize Soviet sovereignty over the archipelago. Nevertheless, the Soviet Union arrived on the archipelago, deported its Japanese residents, and replaced them with Russians.
The history of the Russo-Japanese dispute for the Kuril Islands gets nebulous with the 1956 Japan-Soviet Joint Declaration, a statement signifying the restoration of diplomatic relations between the two nations. According to the leftist Russian news source Meduza, which is based in Latvia, the Joint Declaration declared that the Soviet Union would give the Kuril Islands to Japan but that the USSR discontinued the transfer process in 1960 after Japan allied with the United States. The Database of Japanese Politics and International Relations clarifies that the USSR offered Japan the Habomai Islands and the island of Shikotan upon the conclusion of a peace treaty. However—according to the Japan Institute of International Affairs—the USSR considered the renewal of the Japan-US Security Treaty in 1960 to be in violation of the Japan-Soviet Joint Declaration, revoking the initial offer of the Habomai and Shikotan Islands.
The Joint Declaration bears significance in the twenty-first century, for it was the basis of negotiations between Russian President Vladimir Putin and Japanese Prime Minister Shinzo Abe at the 2018 East Asia Summit. In this meeting, Putin stated that the declaration held no mention of Russia returning the two southernmost Kurils, Habomai and Shikotan, to Japan. Negotiations between Russia and Japan ended there; in 2019, Abe responded by stating that Japan would not sign a peace treaty with Russia until the issue was resolved.
Since the summit, tensions between Japan and Russia have gradually increased, especially since Russian Prime Minister Mikhail Mushustin declared the Kurils a special economic zone (SEZ) in 2023. The Kurils’ status as an SEZ means that Kuril residents now benefit from reduced customs duties on imported goods, most notably those from Japan.
The Russian Perspective
The Russian motive for maintaining control of the Kuril Islands is primarily a military one. The islands are a vital point of exit for both the Russian Pacific Fleet and its military aircraft. They also offer valuable basing options for weapon fires and intelligence collection. Russian Defense Minister Sergei Shoigu confirmed in May 2024 that Russia has constructed numerous surveillance bases and coastal communication facilities on the Kuril Islands. Further reports have emerged that Russia plans to begin a submarine project to prevent the US military from entering the region.
To cement its control of the archipelago, Russia has taken steps to cut Japan off from the Kuril Islands, both economically and culturally. In 2022, Russia suspended its fishing agreement with Japan that had allowed Japanese fishermen to utilize the waters around the southernmost islands. The nationalist Russian news source Interfax claims that Russia took this step because Japan refused to pay quotas for the right to fish; this claim conflicts with Western sources that blame the suspension on Japan’s firm stance against Russia’s invasion of Ukraine. Russia has also banned “extremist maps” that do not show the Kurils as a subject of the Russian Federation. On the islands, Russia has built a monument to the “Soviet hero-soldiers” who liberated “the occupied Kuril Islands,” notably failing to mention Japan as the occupier of the islands. Most interestingly, Pravda, Russia’s national news agency, does not allow users to search for articles about the Kuril Islands on their website.
Japan’s Perspective and the Future of Russo-Japanese Relations
Japan claims sovereignty over the islands and argues that Russia has no legal claim over them. Russia, however, stifles any resistance from the Japanese inhabitants of the islands. For instance, Russian authorities banned a group of Japanese expatriates who disputed Russia’s sovereignty over the Kurils in 2023. Furthermore, Russia has been performing naval drills involving the entire Russian Pacific Fleet in the Sea of Okhotsk, which surrounds the Kurils; Japanese media report that these drills are Russia’s preparation for a Japanese attempt to land on the Southern Kuril Islands.
Russia’s steps to militarize the archipelago indicate that the Kurils will continue to play a major role in Russo-Japanese relations. Russia’s establishment of military infrastructure so close to Japanese territory has significantly escalated tensions between the two nations, despite the facts that 1) Russia does not yet have the military capability to launch an attack on Hokkaido from the Kurils and 2) there seems to be no motive for Russia to launch such an attack. The Japanese government has stated that Japan and Russia should deepen consultation regarding Russia’s military activities on the islands. In contrast, deputy chairman of the Security Council of Russia Dmitry Medvedev said in January 2024: “Nobody’s against the peace treaty on the understanding that…the ‘territorial question’ is closed once and for all in accordance with the constitution of Russia.” Russia therefore lacks Japan’s openness to negotiation.
The Involvement of China, Ukraine, and the United States in the Dispute
Historically, China has supported Japanese sovereignty over the Kuril Islands. Chairman Mao Zedong established this stance in 1964, and subsequent Chinese leaders followed his precedent. However, President Xi Jinping recently overturned this six-decade-long policy by supporting Russia. Just before Russia invaded Ukraine in February 2022, Presidents Vladimir Putin and Xi Jinping signed a pact pledging a “no limits” partnership in diplomacy. Xi has since declared that Russia and China should support each other on matters of sovereignty and territorial integrity.
Perhaps, Chinese support for Russian sovereignty over the Kurils indicates hope for active Russian support regarding China’s territorial claim to Taiwan. Russian Foreign Ministry Spokeswoman Maria Zakharova addressed the issue at a press conference in January 2024:
“The Russian side acknowledges that there is only one China, that the People's Republic of China is the sole legal government representing the whole of China and that Taiwan is an inalienable part of China. The Russian side opposes any form of Taiwan's independence.”
Russia and China seem to be leveraging Taiwan and the Kuril Islands, respectively, to further their respective territorial agendas. Spokeswoman Zakharova’s statement could reflect Russia’s hopes for China to support its claim to the Kuril Islands; an alternative suggestion, and perhaps a more likely one, is that her statement signals Russia’s wishes for China to recognize its claim to Ukraine.
On October 7, 2022, Ukrainian President Volodymr Zelensky signed a decree formally recognizing the Kuril Islands as a Japanese territory temporarily occupied by Russia, likely as a sign of solidarity with another Russian-occupied country. Russia has since used infrastructure from the Kuril Islands in the war against Ukraine, transferring some anti-aircraft missile defense systems from the islands to Ukraine. Additionally, approximately 60 percent of the population of the Kuril Islands is descended from Ukrainians forcibly moved to the archipelago by the USSR after it seized the islands in 1945. There is a lack of coverage on what residents of the islands believe about sovereignty claims; however, the demographic being 60 percent Ukrainian suggests that the islands’ residents might advocate against Russia’s claim to sovereignty.
The United States has been quite passive in its reaction to the Kuril Islands dispute between Russia and Japan. Though not actively involved in the dispute, the United States has received recommendations from various think tanks to deepen consultations regarding Russia’s military activity on the islands. For instance, the Center for Strategic and International Studies, a think tank based in Washington D.C., recommended that the United States renew diplomatic talks with Russia to slow further militarization and prevent accidental escalation in the region. Notably, this recommendation was made in September 2022, after Russia’s invasion of Ukraine earlier that year.
Looking Towards the Future: What Could Japanese Reclamation Look Like?
The ninth article of Japan’s constitution states that Japan cannot be armed or militarized, which puts it at a severe disadvantage in this territorial dispute with Russia. Japan is allowed Jieitai, its Self Defense Forces (JSDF), so it could only utilize force on behalf of the Kuril Islands if Russia were to initiate a war.
As per the Japanese constitution, if the Kurils were given back to Japan, the islands would have to be demilitarized. The question of who might pay for such demilitarization—Russia, Japan, or perhaps any one of the Allied Powers that forced Japan to demilitarize following World War II—must be considered by the international community.
To reclaim the territory, Japan might consider international arbitration; however, this avenue might not be the most effective, given the ambiguous result of the 2018 East Asia Summit Declaration. UN intervention could also be considered, but it is doubtful that Russia would heed the decision of the UN, especially with its disregard for UN opposition to the war with Ukraine. Additionally, Russia’s veto power in the UN makes it unlikely that UN action would bear any fruit.
With the lack of clear communication between Russia and Japan regarding the Kuril Islands and the unwillingness of both parties to compromise, it is unlikely that the conflict will be resolved in the near future. The ambiguity surrounding control over the islands only allows for tensions to rise.
