The Romans making Britain a desert and calling it peace and Germany turning into the surface of the Moon and calling it peace resolved the issues of colonial revolts in Britannia and Germany's penchant to aggressive wars much more clearly than diplomacy ever did. Albeit in both cases the price was steep enough that such a "victory" didn't really matter in the long run in some ways, but at least in Germany's case defeating the Arbeitslager and the Totenlager was more obviously a good thing than with Britannia.