Editing Fu Zuoyi (section)

===Defense of Suiyuan===
After Yan returned to Shanxi in 1931, Fu led Yan Xishan's efforts to "colonize" and take control over the [[Inner Mongolia]]n province of [[Suiyuan]]. Most of the work and settlement of Suiyuan at this time was done by Shanxi farmer-soldiers under Fu's direction. The activities of Fu's farmer-soldiers included mining Suiyuan's iron deposits (24% of all in China) and bringing over {{convert|4,000|acre|km2}} of farmland under cultivation for the first time.<ref>Gillin 128</ref> Fu cultivated a close relationship with [[Zhang Xueliang]] in order to increase the legitimacy of Yan's control over Suiyuan.

In March 1936, [[Manchukuo]] troops occupying [[Chahar Province|Chahar]] invaded northeastern Suiyuan, contesting Fu's control.  These Japanese-aligned troops seized the city of [[Bailingmiao]] in northern Suiyuan, where the pro-Japanese [[Inner Mongolian Autonomous Political Council]] maintained its headquarters. Three months later, the head of the Political Council, [[Demchugdongrub]] declared that he was the ruler of an independent Mongolia ([[Mengjiang|Mengguguo]]), and organized an army with the aid of Japanese equipment and training. In August 1936 Demchugdongrub's army attempted to invade eastern Suiyuan, but it was defeated by Yan's forces under the command of Fu Zuoyi.  Following this defeat, Demchugdongrub planned another invasion while Japanese agents carefully sketched and photographed Suiyuan's defenses.<ref>Gillin 230</ref>

In November 1936 the army of Demchugdongrub presented Fu Zuoyi with an ultimatum to surrender.  When Fu responded that Demchugdongrub was merely a puppet of "certain quarters" and requested that Demchugdongrub submit to the authority of the central government, Demchugdongrub's armies launched another, more ambitious attack. Demchugdongrub's 15,000 soldiers were armed with Japanese weapons, supported by Japanese aircraft, and often led by Japanese officers. (Japanese soldiers fighting for Mengguguo were often executed by Fu after their capture as illegal combatants, since Mengguguo was not recognized as being part of Japan).<ref>Gillin 230–234</ref>

In anticipation of the [[Second Sino-Japanese War]], Japanese spies destroyed a large supply depot in [[Datong]] and carried out other acts of sabotage. In order to defend Suiyuan, Yan placed his best troops and most able generals, including [[Zhao Chengshou]] and Yan's son-in-law, [[Wang Jingguo]], under Fu's command. During the month of fighting that ensued, the army of Mengguguo suffered severe casualties.  Fu's forces succeeded in occupying Bailingmiao on November 24, 1936, and was considering invading Chahar before he was warned by the [[Kwantung Army]] that doing so would provoke an attack by the Japanese Army. Demchugdongrub's forces repeatedly attempted to retake Bailingmiao, but this only provoked Fu into sending troops north, where he successfully seized the last of Demchugdongrub's bases in Suiyuan and virtually annihilated his army.  After Japanese were found to be aiding Demchugdongrub, Yan publicly accused Japan of aiding the invaders. Fu's victories in Suiyuan over Japanese-backed forces were praised by Chinese newspapers and magazines, other warlords and political leaders, and many students and members of the Chinese public. Fu's victories in Suiyuan greatly increased his prestige, and the prestige of Yan Xishan.<ref>Gillin 234–236</ref>