War is not about body count. It is about who can break whose will first. True or false?

Just in my personal opinion, would say that my answer would be "true". For example, General Westmoreland believed in the Vietnam War that the best way to measure success was to kill as many of the enemy fighters as possible. Therefore, he believed that an extremely large amount of bombings by air would kill so many enemy fighters that the enemy Generals would come to the negotiating table sooner or later. And although the enemy did come to the negotiating table a few times near the end of the war after numerous bombings of Hanoi, the enemy's still carried on and their will wasn't broken. In other words, even though the NVA and VC lost a total of about 900,000 fighters compared to the U.S. losses of around 58,000 troops, their will was stronger than the will of the U.S. Would you say my assessment is accurate? And if so, do you see a similar pattern in Afghanistan?