Complex sentence: Chiang did not consider this a good reason to suspect Guo and became enraged when Du presented his view because Chiang believed it implied that all of the Nationalists were corrupt, and that only the Communists were clean.
Split into simpler sentences: Chiang did not consider this a good reason to suspect Guo. He became enraged when Du presented his view because Chiang believed it implied that all of the Nationalists corrupt, and only the Communists were clean.