Do not engage an enemy more powerful than you. And if it is unavoidable and you do have to engage, then make sure you engage it on your terms, not on your enemy's terms.
It is through the dispositions of an army that its condition may be discovered. Conceal your dispositions, and your condition will remain secret, which leads to victory,; show your dispositions, and your condition will become patent, which leads to defeat.
War is a matter of vital importance to the state; the province of life or death; the road to survival or ruin. It is mandatory that it be thoroughly studied.
If we know that our own men are in a condition to attack, but are unaware that the enemy is not open to attack, we have gone only halfway towards victory. If we know that the enemy is open to attack, but are unaware that our own men are not in a condition to attack, we have gone only halfway towards victory. If we know that the enemy is open to attack, and also know that our men are in a condition to attack, but are unaware that the nature of the ground makes fighting impracticable, we have still gone only halfway towards victory.
The general who wins the battle makes many calculations in his temple before the battle is fought. The general who loses makes but few calculations beforehand.