Why can't Sakhalin return to the China version?

This is a historical issue. Due to the invasion of foreign powers, they were forced to sign unequal treaties, mostly to compensate and cede land.

From 65438 to 0858, Russia forced China to cede Sakhalin Island through a series of unequal treaties, such as the Treaty of Love and the Beijing Treaty. 1905, Japan acquired the area south of 50 north latitude of Sakhalin Island, namely Nanhuatai, through the Treaty of Portsmouth. From 1905 and 19 18 to 1925, Sakhalin Island was ruled by Japan.

From 65438 to 0945, the Soviet Union launched the August storm and occupied the whole territory of Sakhalin Island. Japan gave up the sovereignty of Nanhuatai (south of 50 N) in the San Francisco Peace Treaty, but did not hand it over, so the southern part of the island is still a blank area in the map of Japan. At present, sakhalin island is completely controlled by Russia.

Sakhalin Island (Russian: сахалин; Japanese: Huatai island/からふと；; English: Sakhalin), formerly known as Kuye, Kuwu, Gu Wei or Heilongyu in China, translated into Sakhalin Island in Russia (this name comes from Manchu, meaning "Heihekou Island") and called "the next place in the north" (referring to the northern part of Hokkaido) or "Huatai" in Japan.

Sakhalin Island is located in the northeast of Eurasia, southeast of the estuary of Heilongjiang, facing the Sea of Okhotsk in the east, facing the mainland through Miyako Strait in the west, and adjacent to Hokkaido in Japan across Zonggu Strait in the south. It is the largest island in the Russian Federation, under the jurisdiction of Sakhalin State, with an area of about 76400km? .

The northern part of Sakhalin Island is relatively flat, dominated by hills and mountains, and the southern part is composed of East Sakhalin Mountain Range and West Sakhalin Mountain Range, with the highest peak of1420m. The island is rich in forest resources, with coniferous forests in the north, mineral resources such as oil, coal and gold underground, and aquatic resources in coastal areas, which is one of the main producing areas of salmon.

There are more than 6000 rivers and 1600 lakes on the island. The earliest inhabitants of the island are Neva, Ewenki and Ainu. As of 20 10, the population of * * * on the island is 493,000, and most of the residents are Russian immigrants.

Sakhalin Island was ruled directly or indirectly by several dynasties in China in history. 1On September 7th, 689, China and Russia signed the Treaty of Nebuchadnezzar Chu, which determined that the vast areas of Heilongjiang and Ussuri River basins, including Sakhalin Island, belonged to Russian territory.

1858 and 1860, Russia forced the Qing government to cede Sakhalin Island through unequal treaties such as the Love Faint Treaty and the Sino-Russian Beijing Treaty. 1905, Japan acquired the area south of 50 north latitude of Sakhalin Island through the Treaty of Portsmouth. From 1905 and 19 18 to 1925, Sakhalin Island was ruled by Japan. From 65438 to 0945, the Soviet Union launched the August storm and occupied the whole territory of Sakhalin Island. 195 1 year, Japan gave up the sovereignty of South China Terrace (south of 50 north latitude) in the San Francisco Peace Treaty.