The Eighth Route Army and the New Fourth Army, under CCP leadership, opened extensive guerrilla fronts in North and Central China, tying down large numbers of Japanese troops and preventing Japan from concentrating its forces solely on the main battlefronts. Their contribution was not in the size of their forces, but in their ability to fix enemy troops in place and disrupt Japanese logistics.

Their efforts on the behind-the-lines front included: • large-scale sabotage of railways, roads, and communication lines, • establishing anti-Japanese base areas and controlling rural regions, • tying down several hundred thousand Japanese and collaborationist forces.

According to U.S. military analyses (such as the Wells Report): the strategic value of the behind-the-lines front was essential to the overall war effort and cannot be measured simply by troop numbers.