I have only one questyoion about anything working, LG.
If you had been a commander in iraq during bush’s 6 years , was there any point in time when you would have permitted your troops to walk into town to go to a restaurant?
Before Vietnam, the wars we were involved in were conventional with clearly demarcated front lines. Therefore it was perfectly safe to eat in a bistro behind the lines in France in 1918, per your question, or in Italy in 1944.
Restaurant killings have been common in guerrilla wars since then. Example: My Canh floating restaurant in Saigon, 1963. And yet U.S. troops did walk around freely in Saigon before 1975.
This was never the case in either Afghanistan or Iraq, and I doubt it's true for the Russians in Syria or anyone in Libya. It has occasionally been untrue at Fort Hood.
So I don't know if your premise is well-founded, that the litmus test of success in a guerrilla war is whether partisans of one side can parade openly in areas contested or coveted by the adversary: the Parisian banlieus come to mind, and Harlem above 90th Street, and Nuevo Laredo.