Complex sentence: In the spring of 1941 he undertook an assignment in China in 1941 and is credited with obtaining information from a high-ranking German adviser to Chiang Kai-shek about Hitler's plans to attack the USSR in mid- 1941.
Split into simpler sentences: In the spring of 1941 he undertook an assignment in China. He is credited with obtaining information from a high-ranking German adviser to Chiang Kai-shek about Hitler's plans to attack the USSR in mid- 1941.