An independent Scotland could defend itself while saving more than a third of current defence spending, according to a study.
The slimmed-down armed forces would be smaller than those of Denmark and would not be able to operate on the same global scale.
The economic military research was due to be discussed at a wider conference in Edinburgh today on the shape of defence after independence.
Former tank commander Stuart Crawford and economist Richard Marsh prepared the model, intended to be published in full form at a later date. It assumes a desire to defend regional interests and suggests Scotland would have no submarines, aircraft carriers or fast jets.
Mr Crawford, who retired as a lieutenant colonel after 20 years’ service in the Royal Tank Regiment, said: “Others have looked at this from a different position, looking at the population share of the UK or comparing to other countries or the impact on civilian jobs.
“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.”
He said other approaches were flawed: “You wouldn’t look into building hospitals just to give doctors jobs.”
The authors found that Scotland could operate armed forces for about £2 billion, saving £1.3bn compared with the estimated total spent by the Ministry of Defence on Scotland’s behalf.
The model would see a navy of about 20 to 25 ships, including up to eight offshore patrol vessels. The air force would have around 60 aircraft but no Typhoon or Tornado jets, about half that of the Danish air force.
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 that of the Irish.
Mr Crawford said it would be up to politicians to decide whether to use the extra money on building up the military or in other areas such as schools and hospitals.
Scottish Tory leader Ruth Davidson said the report showed Scotland’s “proud military history” would be diminished if voters opted for independence.
She said: “Today we have confirmation that in a separate Scotland, spending on our soldiers, sailors and airmen could be cut by more than a billion pounds; numbers would be decimated and capability destroyed, leaving our uniformed services a third the size of Denmark’s. In terms of the military, as with so much else, it is clear Scotland is better off in Britain.”