Alliance with Communists He allowed Communist agents working under
Zhou Enlai to establish a secret headquarters in Taiyuan and released Communists that he had been holding in prison, including at least one general,
Wang Ruofei.
Early campaigns Fall of Taiyuan Re-establishment of Yan's authority Negotiations with Japanese As the Japanese invasion pushed Yan’s administration into the southwest corner of Shanxi, he established a base there where he lived in sparse conditions for eight years. During this period, Yan practiced what American diplomat
John S. Service described as "eight-faceted glittering gem" diplomacy: maintaining "two faces for the Central Government, two faces for the Japanese, two faces for the Communists, and two more for the people." In 1940 Yan's old friend,
Ryūkichi Tanaka, became chief of staff of the
Japanese First Army. Tanaka initiated negotiations to bring Yan into an anti-communist alliance. Yan proposed a policy of co-operating to oppose the communists, which resulted in several direct meetings, including one with Japanese commander Iwamatsu Yoshio in 1942. While Yan never officially signed a "peace" treaty, a virtual ceasefire existed between his forces and the Japanese by 1944, allowing his troops to cross Japanese lines to attack Communist guerrillas. The efforts of the Japanese Army to convince Yan Xishan to cooperate with them was referenced in the Japanese military's monograph
Senshi Sōsho as the
Operation Targetting Bo (対伯工作) or
Operation Targetting Yan Xishan (対閻錫山工作). The efforts to appease and win over Yan Xishan, the commander of the Second Military Front, were considered a promising operation to undermine the Chinese generals and a first step to collapse the Chongqing government, and was something the Army Ministry, the
East Asia Development Board, and the
China Expeditionary Army placed great importance on. A basic agreement and ceasefire arrangement were concluded on September 11, 1941, and detailed provisions of the ceasefire were concluded on October 27. However, in order to advance the situation, the Japanese side proposed a summit meeting and demanded that Yan Xishan issue a declaration of independence to show that he had severed ties with Chiang Kai-Shek. In response, Yan Xishan only expressed agreement with the fundamental principles of cooperation, but stated that he would only issue the declaration when he received the military funds and weapons as stipulated in the agreement, which delayed the matter. He argued that his Shanxi Army of more than a hundred thousand troops lacked supply, fighting spirit, and strength, and was under close supervision by the Chongqing Central Army while also in conflict with the Communists. The Japanese Army was unsure if Yan Xishan was being sincere or if this was a delaying tactic to build up his army. Moreover, since the agreement was accepted too hastily, the Japanese Army faced difficulty in fulfilling the exaggerated promises they had made to draw in Yan Xishan. Throughout the course of the negotiation, the First Army was sure that Yan Xishan was playing both sides and was constantly drafting up plans to annihilate the Shanxi Army. However, the
North China Area Army was generally hopeful that they could reach an agreement with Yan Xishan, and would always shoot these proposals down. In March 1942, the First Army launched "Operation B" and destroyed a small portion of Yan Xishan's Shanxi troops while attempting to isolate the Shanxi Army from Chiang Kai-shek's troops at the opposite bank of the Yellow River by firing artillery shells at the latter. However, the North China Area Army ordered the suspension of the operation in early April after Yan Xishan dispatched
Zhao Chengshou to negotiate even though the First Army believed that this was a delaying tactic. Then, after Zhao Chengshou returned and Yan Xishan refused to attend a meeting with the Japanese on April 9, the First Army decided to abrogate the existing agreement with Yan Xishan in spite of the wishes of the North China Area Army and the China Expeditionary Army. By April 22, the First Army was intensifying economic blockade and had commenced artillery bombardments on the Shanxi Army, causing Lieutenant General Adachi, chief of staff of the North China Area Army, to contact the army and telling them not to abrogate the existing agreement and engage with the Shanxi Army while the area army was still negotiating with Yan Xishan. In late April, Yan Xishan accepted a proposal by
Su Tiren, the Shanxi Provincial Governor of
Wang Jingwei's Collaborationist Government, for a meeting with the Japanese Army to be held in the Shanxi Army's controlled area of Anping Village on May 5. As the First Army expected however, the meeting ended up with no result and the commander of the North China Area Army secretly notified the Shanxi Army that he would abrogate the initial agreement on May 17. After a breakdown in negotiations, the First Army imposed a severe economic blockade and took coercive actions against the Shanxi Army while simultaneously carrying out appeasement and undermining efforts against individual units. They also distributed leaflets detailing the Anping Village meeting in
Shaanxi in an attempt to sow discord. In June, having given up on appeasing Yan Xishan, the commander of the First Army devised a plan to destroy the core of the Shanxi Army and submitted it to the North China Area Army on the 7th. However, the area army rejected the idea as their plan was to isolate the Shanxi Army and appease them during the Xi'an operation planned for the autumn. The 69th Division launched attacks against the Shanxi Army until it was ordered to cease military actions on July 15, during which the division captured many Chinese troops and used them to form the Shanxi Anti-Communist Army in an attempt by the First Army to undermine Yan Xishan and engage in anti-communist suppressions. Afterwards, there were attempts from the Yan Xishan's side to mend relations and plans from the First Army to once again annihilate the Shanxi Army, but gradually a mood of compromise arose between the two sides, and a renewal effort was adopted to build up partial cooperation and eventually reach full cooperation. As a concrete measure of economic cooperation, the trade of goods began in the spring of 1943. In January 1944, four divisions of the Shanxi Army were relocated to the Fushan and Anze areas for anti-communist measures. In autumn, Yan Xishan dispatched his trusted confidant, Zhu Shouguang, to Taiyuan and stationed him there permanently, likely in an attempt to prepare for his return of Shanxi. After that, despite keeping close contact, there were no more attempts by either side until the war ended. Some Japanese officers, like Colonel Kanachi Sasai, a staff officer of the First Army, believed that the operation toward Yan Xishan had ended in failure and Yan Xishan had succeeded in his objective of self-preservation between the Chongqing government, the Communists, and the Japanese.
Relationship with Japanese after 1945 In early August 1945, Yan met with Japanese Chief of Staff Takahashi Tadashi to discuss the terms of surrender. Yan proposed to "co-opt existing military power", requesting to utilize Japanese military resources and personnel to launch a post-war anti-communist offensive. Takahashi agreed in principle, and following the official Japanese surrender on August 15, Yan returned to Taiyuan on August 30 by an armored train provided and guarded by 500 Japanese soldiers of the First Army. To prevent Communist forces from seizing the province's urban centers, Yan recruited between 10,000 and 43,000 Japanese soldiers and officers to remain in Shanxi and join his "Provincial Defense Army." Japanese commander Sumita Raishiro remained in Taiyuan as Yan's senior advisor until 1947, while Jono Hiroshi served as a key recruiter for these units. Yan justified their presence to the Nationalist government by claiming it was "easier to feed them" in Shanxi than to repatriate them. == Chinese Civil War ==