Jebus wept! Perhaps if you actually read and understood our history rather than merely opening up a history book and clearly not reading it you wouldn't come out with such foolishness as "the fact that the Brits are/always have been responsible for defending our island".
Have a read of this bit of our history and maybe then you'll show some more respect to our protectors.
Even Big Dev realised that our only hope of defending this island when the shit hits the fan is to call in the Brits to do what they do best, batter some Europeans. Without them we might be speaking German or (even worse) French right now.