He who wishes to fight must first count the cost

What enables the wise sovereign and the good general to strike and conquer, and achieve things beyond the reach of ordinary men, is foreknowledge.

The Art of War is self-explanatory

Thus the highest form of generalship is to balk the enemy's plans, the next best is to prevent the junction of the enemy's forces, the next in order is to attack the enemy's army in the field, and the worst policy of all is to besiege walled cities.

Nothing is more difficult than the art of maneuvering for advantageous positions.

To perceive victory when it is known to all is not really skilful. Everyone calls victory in battle good, but it is not really good.

If there is disturbance in the camp, the general's authority is weak. If the banners and flags are shifted about, sedition is afoot. If the officers are angry, it means that the men are weary.