East Asia's top 5 island disputes

East Asia is home to several territorial disputes, which occasionally escalate into regional violence. Many of the island territories are small, isolated from the countries’ mainlands, and sparsely populated. But strategic interests and abundant natural resources make them valuable. Here are five of East Asia’s flashpoints:

Takeshima/Dokdo islands – claimed by Japan and South Korea

The Dokdo islands, also known as Takeshima in Japanese, east of Seoul, is seen seen August 1. (Lee Sang-hak/Yonhap/Reuters)

An island chain in the Sea of Japan, known as the Dokdo islands by Seoul and Takeshima by Tokyo, was claimed by Japan in 1905, prior to its annexation of the Korean peninsula. However, South Korea says the islands became its territory when it declared independence in 1945. The islands are a sore reminder of this colonial past and are patrolled by South Korean police. They were in the spotlight this week after South Korea denied Japanese lawmakers entry into the country because they planned to pay a visit to the South Korean island closest to the disputed chain. Tensions also flared in January 2011 after Japan arrested the captain of a South Korean fishing vessel that had floated into the disputed territory.

Spratly Islands – claimed by China, Malaysia, Philippines, Taiwan, Vietnam, and Brunei

The Spratly Islands are made up of 190 islets in an archipelago spread over 150,000 square miles in the South China Sea. All of the countries have strategic interests in staking a claim to some or all of the islands, as well as economic interests. The islands hold potentially significant oil and gas reserves.

China claims the entire South China Sea, while the other countries claim parts of it. Some of the countries have resorted to military action to demonstrate their claims to the Spratly Islands.

In July 2011, China and the Association of Southeast Asian Nations reached a tentative agreement on “behavioral guidelines” in this region, although it did not resolve the conflicting territorial claims.

Yeonpyeong Island – claimed by North Korea and South Korea

Yeonpyeong Island lies on the South Korean side of the the Northern Limit Line (NLL) of the Yellow Sea, which serves as the maritime border between North and South Korea. North Korea rejects the NLL (and therefore the South Korean claim to the island) because it was designated unilaterally by the United Nations after North Korea and the UN failed to agree on a boundary. Yeonpyeong Island is eight miles from the North Korean mainland, but is claimed by South Korea.

Tensions over the island have occasionally escalated and fatal fire was traded twice in 2010 – once when North Korea unexpectedly shelled the island and another time when it torpedoed a South Korean naval vessel. Military drills by both countries in the area have raised international concerns.

Southern Kuril Islands – claimed by Japan and Russia

The islands of Etorofu and Kunashiri and the Shikotan and Habomai islets were occupied by the Soviet Union in 1945. According to Soviet claims, these islands are a part of the Kuril Islands, granted to the Soviet Union in the post-World War II Yalta and Potsdam Agreements, and the Russian government has upheld that policy. Japan maintains that they are an integral part of the Japanese home islands, illegally seized by the Soviet Union.

The two never signed a formal peace treaty after World War II because of the Kuril Islands dispute, say experts. The US has been a longtime backer of Japan’s claim to the territory.

Russian President Dmitry Medvedev’s staged visit to the islands in 2010 reopened the diplomatic rift.

Diaoyu/Senkaku islands – claimed by China and Japan

The eight Daioyu/Senkaku islands are barren islands northeast of Taiwan. The largest is two miles long and less than one mile wide. The territory is important because the surrounding waters contain oil and natural gas and also serve as fishing grounds.

The islands were previously controlled by Taiwan as part of China, but Japan took over following the Sino-Japanese War. Although Taiwan was handed back to China after World War II, no status was defined for the islands. Interest in the islands was renewed by a UN report in 1969 that said the islands and surrounding waters may contain sizable petroleum reserves.

The US and Japan signed a treaty returning Okinawa and the islands to Japanese control in 1971, although China challenged the agreement.

Sources: Congressional Research Service, US Department of Energy, news and wire services