动摇军心dòng yáo jūn xīn

shake the morale/……即大城市和交通干线之内，各个根据地上的游击战争必须极力向其根据地的四周发展，迫近一切敌人的据点，威胁其生存，动摇其军心，同时即发展了游击战争的根据地，这是十分必要的。(《毛泽东选集》394)…to the big cities and along the main communication lines,the guerrillas must do all they can to extend guerrilla warfare from their base areas as widely as possible and hem in all the enemy’s strongholds,thus threatening his existence and shaking his morale while expanding the base areas.

动摇军心

shaking the army's morale