Had Chiang won the Chinese Civil War, would the USSR have propped up Mao in Manchuria or would they have allowed Chiang to take Manchuria as well?
FTR, the logic behind propping up Mao in Manchuria is that it would make it much easier for the USSR to move materials, equipment, supplies, etc to North Korea. The USSR's border with North Korea was only 12 km but Manchuria has a very long border with North Korea. Indeed, if Manchuria falls to Chiang, Kim Il-Sung might be very vulnerable in North Korea.