On that basis jake we would have allowed Germany to take over the whole of Europe in WWII and then waited until they landed in Dover before defending ourselves.
How about the Falklands , and the other small territories around the world, do you consider them British territory and worth defending ?
The people living there consider themselves British, are they to be given to any tin pot dictator.
How about the Commonwealth e.g Canada and Australia if they were to be attacked are we to say " You are on your own mate ! "