I'd like to think that 1700s USA is a different world to 2000s UK. I really don't see England and Scotland ever going to war again. The only way there might be problems is if the UK powers (Westminster) refuse to allow the Scots to have a democratic say, and Scotland then decide to unilaterally leave the UK regardless. That would cause problems. But even then, it's a stretch to believe it would descend into war.