Independent Scotland = Out of NATO!
Imagine an Independent Scotland. A new country with no formal alliances or ties. Out in the big bad world all alone. I suppose the Scottish Government would apply to join NATO and the European Union.
Both applications could take up to a decade. And that's if they are successful.
The world is experiencing a Resurgent Aggressive Russia that see's the West as an enemy. As we've seen with Ukraine, being allied to NATO and the EU, does you no favours unless you are an actual member.
Scotland would be vulnerable... Why you ask?
Scotland is oil rich, which makes it an attractive place to roll in to and take over. Plus, How embarrassing would it be for the UK and NATO. I'd guess very very embarrassing.
A would be invader would not even need to take the mainland, they would only need to take some of the islands to secure the natural resources of the north sea.
I wouldn't like to dare the Russians, if the time ever came for separation. As we would be easy pickings and unaffiliated. Hence, fair game. They know the game and they play it well.
As NATO unites in the face of this new era of destabilisation. Perhaps it's time for the Nationalists to understand the importance of Union.