I can still remember our unit commander explaining this to us early in our deployment to Afghanistan. We had spent a year in infantry training, learning how to kill and destroy things. But then, sort of at the last minute, the Army attempted to reign us in, reminding us that it wasn't all about destroying things, it was also important to win hearts and minds! Winning hearts and minds is perhaps, about the most important thing you can do to win a war. You need the indigenous population, whether they be French (World War II) or Afghans (Afghanistan) to be on your side. If you don't have the native population, they can make staying in-country exceedingly difficult.