1945年8月15日，日本投降，二戰結束。根據年初雅爾達會議的安排，朝鮮半島由美國與蘇聯共同代管，並在三八線劃地而治

1945年8月15日，日本投降，二戰結束。根據年初雅爾達會議的安排，朝鮮半島由美國與蘇聯共同代管，並在三八線劃地而治。同年8月26日，北方成立「平安南道人民政治委員會」作為臨時行政機構。10月10日，朝鮮共產黨北朝鮮分局成立，11月18日改名為「北朝鮮共產黨」，金日成當選為第一書記。1946年2月，北方設立國家最高權力機關「北朝鮮人民會議」，2月8日建立了以金日成為委員長的「北朝鮮臨時人民委員會」作為最高行政機關。11月3日，北方各道市舉行地方人民委員會代議員選舉。1947年2月17日成立了最高權力機關「北朝鮮最高人民委員會」和最高行政機關「北朝鮮人民委員會」，並開始土地改革。

1948年4月29日「北朝鮮最高人民會議」通過了《朝鮮民主主義人民共和國憲法》，並在8月25日舉行普選，產生朝鮮最高人民會議議員。同年8月15日，大韓民國率先正式成立，緊接著9月9日，朝鮮民主主義人民共和國也宣布成立，金日成出任內閣首相。此時，朝鮮半島兩個政權對峙的局面正式誕生。12月，蘇聯軍隊撤出半島北部。1949年6月28日朝鮮成立「祖國統一民主主義戰線」，實際上成為最高人民會議內部的政黨聯盟，控制了議會百分之百的議席。

1945年8月，第二次世界大戰結束後，根據年初雅爾達會議的安排，原日占朝鮮由蘇聯和美國共同託管，蘇聯紅軍和美軍以北緯38度線為界分別進駐朝鮮半島北部和南部。此後朝鮮半島先後被劃分為南北兩塊勢力範圍：由蘇聯軍事政府管理的北部以及美軍政廳統治的南部，兩者在1948年後分別獨立為「朝鮮民主主義人民共和國」及「大韓民國」。

第二段维基百科对大韓民國的叙述模糊不清。比较英文版：

In the South, the United States appointed and supported the former head of the Korean Provisional Government Syngman Rhee as leader. Rhee won the first presidential elections of the newly declared Republic of Korea in May 1948. In the North, the Soviets backed a former anti-Japanese guerrilla and communist activist, Kim Il Sung, who was appointed premier of the Democratic People's Republic of Korea in September.^[94]

In October, the Soviet Union declared Kim Il Sung's government as sovereign over both the north and south. The UN declared Rhee's government as "a lawful government having effective control and jurisdiction over that part of Korea where the UN Temporary Commission on Korea was able to observe and consult" and the government "based on elections which was observed by the Temporary Commission" in addition to a statement that "this is the only such government in Korea."^[95] Both leaders engaged in authoritarian repression of political opponents.^[96] South Korea requested military support from the United States but was denied,^[97] and North Korea's military was heavily reinforced by the Soviet Union.

Born in Hwanghae Province, Joseon, Rhee attended an American Methodistschool, where he converted to Christianity. He became a Korean independence activist and was imprisoned for his activities in 1899. After his release in 1904, he moved to the United States, where he obtained degrees from American universities and met President Theodore Roosevelt. After a brief 1910–12 return to Korea, he moved to Hawaii in 1913. In 1919, following the Japanesesuppression of the March First Movement, Rhee joined the right-leaning Korean Provisional Government in exile in Shanghai. From 1918 to 1924, he served as the first President of the Korean Provisional Government until he was impeached in 1925. He then returned to the United States, where he advocated and fundraised for Korean independence. In 1939, he moved to Washington, DC. In 1945, he was returned to US-controlled Korea by the US military, and on July 20, 1948 he was elected the first president of the Republic of Korea by the National Assembly, ushering in the First Republic of Korea.

As president, Rhee continued his hardline anti-communist and pro-Americanviews that characterized much of his earlier political career. Early on in his presidency, his government put down a communist uprising on Jeju Island, and the Mungyeong and Bodo League massacres were committed against suspected communist sympathisers, leaving at least 100,000 people dead.^[2] Rhee was president during the outbreak of the Korean War (1950–1953), in which North Korea invaded South Korea. He refused to sign the armistice agreement that ended the war, wishing to have the peninsula reunited by force.^[3][4]