Interesting logic in that statement.
Even if I agreed with your premise, you don't always fight a war because you think you can win. Sometimes you fight because you have no other choice.
Now the war on poverty, the war on drugs, very well may not be winnable but the war on terror must be fought at very front, win, lose or draw. We have no other choice.
Don't let MNJohnnie know you are repeating a slogan, evad.
(See his post #302)