The best victory is when the opponent surrenders of its own accord before there are any actual hostilities...It is best to win without fighting.

One defends when his strength is inadequate, he attacks when it is abundant.

So it is that good warriors take their stance on ground where they cannot lose, and do not overlook conditions that make an opponent prone to defeat.

If an enemy has alliances, the problem is grave and the enemy's position strong; if he has no alliances, the problem is minor and the enemy's position weak.

The enemy's spies who have come to spy on us must be sought out, tempted with bribes, led away and comfortably housed. Thus they will become double agents and available for our service. It is through the information brought by the double agent that we are able to acquire and employ local and inward spies. It is owing to his information, again, that we can cause the doomed spy to carry false tidings to the enemy.

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.

Opportunities multiply as they are seized.