interesting question, as others have said for your family, your community, as those who died in WW1, WW2 did, they may not have thought about King and country, most don't, nor Queen and country, until perhaps push came to shove. If you were under threat of invasion, say by Germany, hypothetically speaking, they bombed us, sent troops across the channel, would you sit idly by and let it happen, if they had another Hitler on the horizon, would that then persuade you to protect your homeland, because i know i would, old as i am.
I posted a question of this nature long time ago, and stated the obvious, that we are now a very mixed bag of people's like it or not, and would those who have come from Pakistan, India, Somalia, US, Afghanistan France and as many countries you can think of who have settled here fight for UK, would Scotland if it gains it's independence, i don't think they would, after all if it came to another world conflict, it might mean British fighting against some of their kindred, how would have pan out.