So the important thing in a military operation is victory, not persistence.

Invincibility lies in the defense; the possibility of victory in the attack.

It is the rule in war, if ten times the enemy's strength, surround them; if five times, attack them; if double, be able to divide them; if equal, engage them; if fewer, defend against them; if weaker, be able to avoid them.

So the important thing in a military operation is victory, not persistence.

If I wish to engage, then the enemy, for all his high ramparts and deep moat, cannot avoid engagement; I attack that which he is obliged to rescue.

When envoys are sent with compliments in their mouths, it is a sign that the enemy wishes for a truce. If the enemy's troops march up angrily and remain facing ours for a long time without either joining battle or removing demands, the situation is one that requires great vigilance and circumspection. To begin by bluster, but afterward to take fright at the enemy's numbers, shows a supreme lack of intelligence.

Ground which can be abandoned but is hard to re-occupy is called entangling.