There is a lesson for people governing global empires here - don't allow major wars to blow up on your borders. Or, ideally, anywhere. Maybe spend some time promoting peace and prosperity. Train the diplomats in diplomacy.
You'll notice that the US solution at the end of WWII was completely different to the European settlement at the end of WWI. And the US approach to warring was a lot more staid than the UK's. These are basic matters of competence.