The reality is that the military of the Chinese Communists has been phenomenally successful whether the liberal democracies and their militaries in the West like it or otherwise. The record of success, despite being embellished undoubtedly by propaganda, is quite plain to see. In many operations of the 1948-1949 campaign, the communists were able to smash vast and American-equipped KMT armies. In the guerilla campaigns of Mao, Lin Biao and others, the communists were able to time and again, defy KMT offensives while maintaining support among the populace.
The communists had understood the political dimensions of warfare and that it could not be separated from military operations.
'Chinese Warfighting: The PLA Experience since 1949' by Mark A. Ryan, David M. Finkelstein, Michael A. McDevitt.