Could Britain still sustain a global Commonwealth?

How many former colonies could Britain afford to maintain today if they had remained associated after the war?

It depends on the constitutional form; colonies would strain British budgets, while a genuine federation could pool a global economy and sustain a larger navy.

Retaining territories as dependencies would impose significant budget demands on Britain. Constitutional structure matters more than a simple count of territories. A federated polity would combine populations and economies across the world, creating a larger naval requirement. It would also possess a broader tax and industrial base capable of sustaining that fleet.