兔死狗烹 [ tùsǐgǒupēng ]: lit. to boil the hound once it caught the rabbit (idiom); fig. to get rid of sb once he has served his purpose
治大国若烹小鲜 [ zhìdàguóruòpēngxiǎoxiān ]: ruling a large nation is like cooking a small delicacy (idiom); effective government requires minimal intervention