Sir Malcolm made his claim at a conference on the impact of Scottish independence organised by the UK’s leading defence thinktank the Royal United Services Institute (Rusi), where he also claimed it could “take at least 10 to 15 years and probably more than a generation” to get nuclear weapons out of Scotland.
The former defence secretary also questioned how Scotland could afford to set up its own security services with MI5, MI6 and GCHQ costing the UK £2 billion a year, and suggested it could cost Scotland at least £200 to £400 million a year.
During the discussions he pointed out that two thirds of the forces in the UK are logistics and other back up services.
He said on a similar model this would mean that the 15,000 planned by the SNP for the Scottish forces would have just 5,000 combat troops.
He described the SNP plans as “back of the envelop type stuff.”
But Sir Malcolm’s was attacked by SNP defence spokesman Angus Robertson for suggesting that two thirds of Scottish regimental personel were from outside Scotland.
Refusal to discuss defence
Mr Robertson argued that the SNP’s plans to spend £2.5 billion on defence was consistant with Denmark, which is a similar size.
He also said that if Scotland becomes independent “more will be spent on procurement in Scotland” than has been the case.
And he attacked the UK Government for not having technical discussions with the SNP Scottish Government over defence ahead of the referendum.
He said: “It is in the interest of Scotland and the rest of the United Kingdom to take the security dimension seriously now, which is why it is irresponsible for the UK government to refuse technical discussions ahead of the referendum with the Scottish Government.
“It is also misguided for the UK Ministry of Defence to increasingly refuse to answer parliamentary questions which would be beneficial to the process of understanding.”
Former Labour defence secretary Lord Des Browne pointed out that currently about £1.8 billion is spent on defence procurement in Scotland, mainly shipbuilding which could be lost with independence.
Of the SNP’s prposed £2.5 billion expenditure he added: “When I hear the shopping list of what they want I see experts shaking their heads because it will cost more than £2.5 billion.
“It is not that Scotland is too wee to do it, it can do it, but it has to find the resources to do it.”Former Lib Dem leader Sir Menzies Campbell spoke of the international conserns about independwence.
He told the audience that while the US government is not taking a public position on it, “privately” the State Department “is concerned.”