In 1945 the Japanese empire collapsed and the Japanese puppet state of Manchukuo followed its sponsor into oblivion. Technically, the area then known as “Manchuria” was returned to China after a short Soviet occupation (it was largely the Soviets who drove the Japanese from northeast China in 1945). However, at the time China was in the midst of a civil war between communists and nationalists. Thus, the transfer did not initially mean much.

As of 1945, some 1.7 million ethnic Koreans resided in Manchuria. Roughly one-third – some 600,000 people – left within a few years of the collapse of Manchukuo and went back to Korea. In most cases these returnees believed that they would have a better future in their newly independent home country, but some may have chosen to leave northeast China because of their earlier collaboration with the Japanese or Manchukuo authorities. However, the majority remained and soon overwhelmingly threw in their lot with the communists.