Personally I dont believe scotland should split from the UK, it just doesn't make any sense to me. Besides it would make both countries weaker in alot of ways, and theoretically lets says scotland becomes its own country but doesnt become a part of NATO or EU, someone could invade them and the UK would have a bad new neighbour just above their country, can't say that would be any good for them. UK has survived so long by being a hard island to take, its like leaving one side of your island up for grabs.
Just who is going to invade Scotland? For that matter, who is going to decide to invade any Western European country unchallenged? What century do you think we're living in?
I say they should go for it and be independent. Smaller, more localized governments FTW.
Russia for instance? Scotlands army will never be able to match that of the UK, could be a nice way to enter the island.
But to me the UK is a strange place, Wales, Scotland, England. I would think that all of these areas would just be happy being a part of Great Britain, being under just one nation. I dont know though, I've never been there, never talked to the people. It would make sense though if Northern Ireland became a part of Ireland again though. The British mistreated the Irish for many years, theres no doubt about that.