The art of war, then, is governed by five constant factors, to be taken into account in one's deliberations, when seeking to determine the conditions obtaining in the field.
These are: (1) The Moral Law; (2) Heaven; (3) Earth; (4) The Commander; (5) Method and discipline.
All warfare is based on deception.
When you engage in actual fighting, if victory is long in coming, then men's weapons will grow dull and their ardor will be damped.
Note: "if victory is long in coming, then men's weapons will grow dull and their ardor will be damped"