sentences:  These warlords were only interested in keeping their own power and defected to the Japanese side when Japanese invaders offered to let them keep their power in exchange for their collaborations.After World War II, these forces of former Japanese puppet regimes once again returned to the nationalist camp for the same reason they defected to the Japanese invaders.Oblivion, it was difficult for Chiang to immediately get rid of these warlords for good as soon as they surrendered to Chiang and rejoined the nationalists, because such move would alienate other factions within the nationalist ranks, and these former Japanese puppet regime's warlords could still help the nationalists to gain more territories by holding on to what was under their control until Chiang completed the deployment of his own troops to take over.