Hu Zongnan
His most critical contribution came in March 1947, when Hu Zongnan, under orders from Chiang Kai-Shek, moved to attack Yan'an. Although Hu was successful in the "lighting attack" operation to sack Yan'an, he was unable to capture or kill the CCP leadership, as Xiong Xianghui had secretly managed to warn the CCP leadership two weeks prior to the Nationalist assault. Xiong's warning gave the CCP leadership enough time to relocate to Zhangjiakou. Xiong had also provided the CCP with Hu's battle plans and elements of private conversations he had overheard with Chiang Kai-shek, which would cause immense damage to Hu's forces and to the wider Nationalist war effort thereafter.