After the surrender of Japan and the end of the Second World War, Yan Xishan was notable for his ability to recruit thousands of Japanese soldiers stationed in northwest Shanxi in 1945, including their commanding officers, into his army. By recruiting the Japanese into his service in the manner that he did, he retained both the extensive industrial complex around Taiyuan and virtually all of the managerial and technical personnel employed by the Japanese to run it. Yan was so successful in convincing surrendered Japanese to work for him that, as word spread to other areas of north China, Japanese soldiers from those areas began to converge on Taiyuan to serve his government and army. At its greatest strength the Japanese "special forces" under Yan totaled 15,000 troops, plus an officer corps that was distributed throughout Yan's army. These numbers were reduced to 10,000 after serious American efforts to repatriate the Japanese were partially successful. Yan's Japanese army was instrumental in helping him to retain control of most of northern Shanxi during much of the subsequent Chinese Civil War, but by 1949 casualties had reduced the number of Japanese soldiers under Yan's command to 3,000. The leader of the Japanese under Yan's command, Hosaku Imamura, committed suicide on the day that Taiyuan fell to Communist forces.