置之死地而后生: deploy troops in such a way as to leave no room for maneuver or route for escape so that the soldiers will fight for their dear lives out of desperation and eventually win the battle
置之死地而后快: would be satisfied with nothing short of someone's destruction; will be content with nothing less than sb.'s destruction; will not be satisfied until someone has been destroyed; in an atte
三思而后行: first think before you actlook before you leapscore twice before you cut oncesecond thoughts are best / think before you dothink twice before doing somethingto think before i talk