Lean years follow in the wake of a great war. Just do what needs to be done. Never take advantage of power. Lao Tsu recommends flexibility over force. At his death he is hard and stiff.
Green plants are tender and filled with sap.
At their death they are withered and dry. Therefore the stiff and unbending is the disciple of death. The gentle and yielding is the companion of life. Thus an army without flexibility never wins a battle. A tree that is unbending is easily broken.