Retired Black Watch commander Lieutenant General Sir Alistair Irwin and former UK security and intelligence coordinator Sir David Omand gave their frank assessments at a conference on global security at the University of Glasgow.
The two men were billed as the keynote speakers on the first day of a conference also attended by academics from universities across Scotland, England and the US.
Sir Alistair was commissioned into the Black Watch in 1970, serving in Northern Ireland, Edinburgh and West Berlin. He retired as adjutant general in 2005 after overseeing a time of major restructuring in the Army.
In his opening address to the conference, he said that while a Scottish defence force is possible, there is “no question” the country and the rest of the UK is better off under the current military arrangements.
Anecdotal evidence suggests there would be difficulties in recruitment with an independent force, from soldiers to high-ranking officers and civil servants, he said.
A relatively low budget would cause problems filling vital supporting and training functions for the front line, according to Sir Alistair.
“The result of a split, in my military opinion, would be a British Isles collectively less well defended and whose global interests would be much less well served than they are now,” he said.
“Lurking very close to the surface is the nagging thought that with tight budgets and ever-increasing demands being made upon them, to spend money in Scotland replicating all the existing UK-wide policy, administrative and practical functions that are needed to sustain a defence force seems profligate, to say the least of it.
“An independent Scotland would, of course, be perfectly capable of establishing - I don’t necessarily mean manning - a Scottish defence force with maritime, land and air components, albeit of limited capability.
“But from a military point of view, there is, I think, little doubt that the nation and its interests, despite the best intentions and efforts of all who would be involved, would not only be less well protected than they are now but, more to the point, would actually be inadequately protected.
“Whatever the size, shape and quality of a Scottish defence force, in defence terms, there is no question that we are far better off as we are and there doesn’t seem to be any defence reason why we should want to swap current arrangements with new and lesser ones.”