Huh? The Vatican is a city-state, if you like, but neither the City of London or DC are; the City of London is under British jurisdiction, while DC is under US jurisdiction. None of the three "own" each other.
A source for what? The claim that DC is under US jurisdiction and that London is under British jurisdiction? Sure; see the incorporation documents for DC here, and observe the ongoing state of affairs in which US law is enforced in DC in US courts.
What you don't understand city states? The Vatican, City of London and DC?
Huh? The Vatican is a city-state, if you like, but neither the City of London or DC are; the City of London is under British jurisdiction, while DC is under US jurisdiction. None of the three "own" each other.
You have sauce for that?
A source for what? The claim that DC is under US jurisdiction and that London is under British jurisdiction? Sure; see the incorporation documents for DC here, and observe the ongoing state of affairs in which US law is enforced in DC in US courts.