Japan voices strong protest over Putin's visit to disputed Kuril island

Japan has lodged a strong protest with Russia following President Vladimir Putin's visit to a disputed island in the Kuril chain. Russian state media reported on Thursday that Putin had visited Iturup Island, known as Etorofu in Japan, one of the four islands at the centre of a decades-long territorial dispute between the two countries.

Japan's Foreign Minister Toshimitsu Motegi said the islands are "inherently Japanese territory both historically and under international law, and the Government of Japan strongly protests this visit". The visit, he said, runs counter to Japan's position and is unacceptable.

The Kuril Islands lie between Japan's northernmost island of Hokkaido and Russia's Kamchatka Peninsula. The four southernmost islands – Iturup, Kunashir, Shikotan, and Habomai – are claimed by Japan, which refers to them as the Northern Territories. They have been administered by Russia since the Soviet Union annexed the entire chain at the end of World War Two. Around 17,000 Japanese residents were deported from the islands at that time.

The territorial dispute has been the main reason Moscow and Tokyo have not signed a formal peace treaty after World War Two, leaving a legal end to their wartime conflict unresolved. Successive governments in both capitals have tried to negotiate a settlement, but the issue remains a sticking point.

The roots of the dispute go deeper than the Second World War. Under the Treaty of Shimoda of 1855, the two countries agreed that the four southern islands would belong to Japan and the rest of the chain to Russia. A later treaty in 1875 saw Russia hand over the entire chain to Japan in exchange for full control of Sakhalin Island. After Japan's surrender in 1945, the Soviet Union took control of all the islands, leading to the current impasse.

Putin's visit to Iturup was significant as it reaffirmed Russian control over the territory. According to Russian state media, during his visit he sampled fish roe and spoke with local residents. The visit was reported as part of his working trip to the country's Far East.

Strategically, the islands hold considerable importance for Russia's military posture in the Pacific. Iturup hosts Russia's primary military air base in the region. Moscow has also conducted military exercises near the islands, drawing condemnation from Japan. Last month, Chinese and Russian naval warships sailed through a strait in the Kuril islands during a joint patrol, underscoring the strategic dimension of the area. The islands are positioned between the Sea of Okhotsk and the Pacific Ocean, offering access to important naval routes.

Japan's protest is the latest in a series of complaints over Russian activities on and around the islands. Tokyo has consistently maintained that the islands are its inherent territory and has called for their return. Russia, however, holds that its sovereignty over the islands is lawful and based on the outcome of World War Two.

Despite the diplomatic friction, both countries have shown interest in expanding economic cooperation, particularly in energy and maritime resources. However, the territorial dispute continues to overshadow their bilateral relations, and no breakthrough appears imminent.