I thought it was meant to be funny as well as thought-provokimg and hitting response to their BSs, at least to reach those "in the middle" who are capable of thinking. Nobody cares about hippies anymore, so the reference maybe "lost in translation" and message wasted...
Let me clarify (2). The "progressives", if anything, are anti-"tradition"... "Tradition" to them is not something to be valued, more to the point - it is to be discarded and/or impugned. To those "in the middle" who will see the sticker, it's not inspiring or consequential or even important. "Never brought peace" or something similar to that shows the result or consequences of "Retreat and Surrender
Re (3), I think your original phrase, stating that "We Won the war", is much better in that it does show a "completion" of the "war" phase (we already won), because "Winning the War = 1/2" may imply that we haven't yet, or at least doesn't state that this part of the job is finished. And, of course, "winning the peace" takes a lot longer than 1/2 of the time of the whole operation, as is usually with the maintenance of the project after finishing the project itself. So you'd want to put emphasis on the second part of the job ("winning the peace") not being finished, while leaving no uncertainty about the first one ("winning the war") Also, one reason I deliberately put in "help" was to show that we are not alone and not even primary force in "winning the peace"... but still making sure that it requires military presence and/or action, hence "win" seems better suited for the second part (the peace) than original "complete" or "finish".
Hopefully, this helped clarify my thought process on these instead of making it more obscure. Or, maybe, I am too darn nitpicking today. :~)
When I said directed at them, I meant liberals. I think I like “We Won the War, Now Let’s Win the Peace” some. But I wanted to make the point that ousting Saddam was only half the job. Pulling out now leaves the job unfinished.