Win the War?

I've been pondering this question all morning, so I'm going to give it out to you, the blogosphere: how exactly does one "win" a war? Or, how do you define "winning the war?"

This question has been rolling around in my brain since I watched the morning news as I was getting ready. One of the stories on the news was about how if one of the presidential candidates had a shot at winning the upcoming election, he had to "prove to America that we're winning the war." Which made me wonder: how do we really know if we're winning the war? Are there benchmarks or signs that I should be looking for? What does "winning" look like?

Does anyone really "win" in war? I dunno, but I sure wish that someone would clear it up for me...