September 1945: US forces land in South Korea. Grassroots people's committees already governing locally are dissolved by military decree. USAMGIK bans the People's Republic of Korea structures in December. American officers with no Korean language skills are appointed as provincial governors.
1946-1947: US military government suppresses labor unions, peasant land seizures, and student organizations. Political parties to the left of center are driven underground or banned. Syngman Rhee returns from exile with US backing.
May 1948: US-supervised elections held only in the South. Left and moderate parties boycott or are suppressed. Rhee elected president. DPRK founded in September in response, after separate elections in the North through the remaining people's committees.
April 1948: Jeju uprising begins against separate Southern elections. US retains operational control of ROK military via executive agreement with Rhee. Brigadier General William Roberts approves martial law. Scorched-earth campaign November 1948 to February 1949. 25,000-30,000 civilians killed.
1949: Border clashes along the 38th parallel intensify. ROK forces initiate multiple cross-parallel raids in Ongjin Peninsula and other sectors. Declassified US field reports document Southern artillery provocations and infantry incursions. Approximately 8,000 ROK soldiers and police killed in border fighting and counter-insurgency before June 1950.
Early 1950: ROK military buildup continues with US equipment and training. DPRK prepares defensive-offensive posture. Diplomatic efforts to reunify the peninsula fail as US rejects proposals for all-Korean elections under neutral supervision.
June 25, 1950: DPRK forces cross the 38th parallel. This is the escalation of a civil conflict shaped by five years of imposed division, political repression in the South, and armed border warfare. Not an isolated invasion. The culmination of material conditions created by foreign occupation and class conflict.
This is all not to mind the horrors the US and occupied Korea inflicted on the DPRK during the Korean war. The war the US waged on the DPRK was a campaign of extermination. Between 1950 and 1953, one in five to one in four DPRK civilians were killed. Every town, factory, school, and hospital was reduced to rubble. Survivors lived in caves. US Air Force records show over 635,000 tons of bombs and napalm were dropped on the North. That is more than 100,000 tons above the entire Pacific theater of World War II. The US military requested nuclear strikes multiple times. They were held back only by the risk of Soviet retaliation, not by restraint. Anyone who defends the US intervention stands on the same ground as Adolf Eichmann.
Some sources:
https://en.prolewiki.org/wiki/United_States_Army_Military_Government_in_Korea
-https://en.prolewiki.org/wiki/People%27s_Republic_of_Korea_(1945%E2%80%931946)
https://www.kpolicy.org/post/early-cold-war-genocide-the-jeju-4-3-massacre-and-u-s-responsibility
https://www.marxists.org/history/international/comintern/1951/korea.htm

