Originally Posted by Inst

I think the reason Sun Zi was so cautious was because of his situation. In the Warring States period, each state had many neighbors, some of them capable powers and none of them willing to settle for less than total victory. Attrition in this case does not mean that your kill:loss is on parity with your immediate opponent, it has to be on parity with all your neighbors.

Imagine if the moment the Prussians reached Paris, the Austro-Hungarian Empire would immediately launch an attack on Prussia simply for the sake of taking advantage of a distracted state.