Foiling the enemy’s strategy is an important principle proposed by Sunzi the ancient military strategist. In his view, war is waged at different levels, all of which have a significant impact on the outcome. Armed attacks will do great damage to both sides, so they should be avoided if at all possible. Those who are good at leading armies should be able to use stratagems to eliminate the threat of enemy attack in advance or clear the obstacles to their own armed forces to achieve their strategic goals at minimal cost.

The preferred way is to foil the enemy’s plans, the next best to use diplomacy, failing that to attack the enemy’s forces, and the least desirable is to assault the enemy’s cities. Assaulting cities is a last resort when all else has failed. (The Art of War)