Scotland's politicians must consider the shape of a post-independence military, defence experts have urged.
With the deadline for an independence referendum just over two years away, former soldiers and academics have called for firm policy decisions to be made on the future of the Scottish armed forces should the country opt out of the UK.
At an event hosted by The Scotsman newspaper in Edinburgh, politicians and officials were urged to start thinking about intelligence gathering, anti-terrorism and how a defence force would be recruited before the referendum
Former SAS deputy commander Clive Fairweather said Scotland's oil and gas platforms are the most likely targets for any terrorist attack.
He argued the case for a new special forces squadron to replace the functions of the SAS. He said about 75 members would be required to form the squadron, at an estimated cost of £10m to establish and £5m a year to run. It would take three years to prepare, he said.
Mr Fairweather added: "Where are we going to get these individuals? On the announcement of independence, I'm sure patriotic Scots SAS and SBS will be rushing north to become the backbone.
"Actually I reckon that would be about a handful. The remainder will probably stay on for a more professional opportunity elsewhere. That would be my guess."
To counter those concerns, he said preparation must start now.
"We can't wait until day one of independence," he added.
"Some preparation will have to be made to cobble that force together beforehand. There will have to be a very fuzzy overlap where English special forces would still come to the rescue before we're finally able to go ourselves."
The two worst terrorist attacks in Scotland, Lockerbie and Glasgow Airport, were respectively a mistake and an afterthought, he said.
He added: "We won't find out until after independence quite who our enemies are and how they're going to operate."
Professor Hew Strachan, a military historian and adviser to the Ministry of Defence (MoD), said defence policy focuses too often on the military "at the exclusion of the navy or air force".
He added: "(Scotland's) coastline, its coastal waters, its islands, to say nothing of its shipping and trading heritage, ought to make its maritime and naval inheritance much more powerful than its military one."
The conference also heard from Stuart Crawford who retired as a lieutenant colonel in the Royal Tank Regiment.
Working with economist Richard Marsh, he suggests Scotland could defend itself with a slimmed down military, making savings of around £1.3bn.
Mr Crawford said: "We decided to approach this by asking first what the armed forces is for, what you need to fulfil the purpose and how much that would cost."
His model would include a navy of about 20 to 25 ships. The air force would have around 60 aircraft but no Typhoon or Tornado fast jets.
The army would have an HQ and two brigades but no tanks or heavy artillery. It would have between 10,000 and 12,500 personnel, about one-third the size of the Danish army but larger than the Irish military.
Meanwhile, The Prime Minister could be quizzed tomorrow over possible cuts to Scotland's army regiments.
The Black Watch based at Fort George in Inverness could be forced to merge with the Argyll and Sutherland Highlanders under plans to restructure the army.
Other units could lose their cap badges, but the Ministry of Defence insists that no decisions have been made.