Have I got this right?
As a UK citizen going to the USA for a short holiday I have to obtain a visa or, if I'm considered suitable, can apply for the visa waiver scheme.
I will also have to pay £9 to enter the country.
A US citizen coming to the UK for short holiday does not need a visa and there is no charge to enter the country.
Seems a bit one-sided but as our prime minister has told the world we are junior partners to the USA I suppose we must doff our hats to the mighty Sam and accept the fact gratefully that we are allowed to enter his country at all - those who want to go that is.
Air passenger duty applies to everyone, whether British or overseas nationality, who flies from a UK airport so that is at least even-handed even if the duty itself is controversial.