How soon we forget!
And let's not forget, as much as we'd like to, the wars fought against the various Indian tribes in the 19th Century.
Still, each war had but two sides and two ultimate commanders. Lee surrendered to Grant at Appomattox. Crazy Horse, after routing Custer's 7th Cavalry, eventually was forced to surrender.
Who, in this "War on Terror," will be designated to surrender for the terrorists, and, assuming the American military commander in the Middle East is empowered to accept such a surrender, how will the thousands of terrorists be identified, rounded up and imprisoned?
Yes, there could be trials for war crimes. But historically, only the higher-ups are put on trial. The troops are given amnesty.
No doubt there are entire sections of the Pentagon already making plans for such things, just in case.
They'll continue making plans for the next century if present policies remain in effect.
As you indicate, this thing may never be over