What? A very muddled question or ideas on what is taxable.
The tax if any is due upon each part of th transaction...not dependent on a condition subsequent... a repurchase or whatever....and how...
The US and the UK.
Both countries are of course members of NATO, so the issue is whether there is an additional agreement. There's something that some British politicians like to call the 'special...
By having the correct subject verb agreement you show that your writing skills are good. Somebody with poor writing skills will write with poor grammar. Also your writing will be understood...