An important part of a review is to incorporate the key and undisputed facts about current defence spending, military capability and footprint, including here in Scotland.
What we need now is a Scottish defence review, because it is abundantly clear UK policy is leading Scotland in the wrong defence direction, with virtually no public support. This involves a dramatic decline in the conventional defence footprint, at the same time as planning to impose a new generation of Trident nuclear weapons in Scotland, albeit in possibly diminished form. Pressures on military service personnel and their families at the present time are unprecedented. Dangerous tours of duty in Afghanistan, general military overstretch, and a changing society have contributed to major challenges.
It is vital that a Scottish review ensures that defence policy reflects Scotland's priorities and preferences, and is focused on the future. As Scotland on Sunday reports today, substantial research at Westminster, including a series of parliamentary questions, have informed an SNP study utilising defence specialists in the House of Commons Library.
The conclusions are striking and for many observers will be unexpected. In contrast to the conventional wisdom about a significant and well-funded UK defence presence in Scotland, the facts are entirely different.
Not only have thousands of defence jobs been cut in Scotland since Labour came to power in 1997, but there has been a multi-billion-pound defence underspend north of the Border, as well as a litany of base closures and regimental amalgamations.
While abolishing and amalgamating the historic Scottish regiments and dissolving the "Golden Thread" are the most visible manifestations of UK defence cuts in Scotland, they are not the only ones. Since 1997, there are 9,500 fewer defence jobs in Scotland. That translates into 1,930 fewer service jobs, 4,570 fewer civilian jobs and 3,000 fewer jobs based on direct MoD expenditure.
Between 2002 and 2006 alone, the total accumulated defence underspend in Scotland – ie comparing our share of UK defence spending with population share – was a mammoth 4.363 billion.
This shocking trend is replicated over a similar timespan when it comes to defence jobs, where the cumulative underspend on civil and service personnel was 869.9million.
This trend continues when one looks at military material, where the total underspend in one year was 750m. In that same year, only 4.4 per cent of the MoD's global equipment and non-equipment budget was spent in Scotland.
What these statistics show is that Scottish taxpayers are disproportionately contributing huge sums towards the UK Ministry of Defence, at the same time as the UK's conventional defence footprint in Scotland is disappearing at an unprecedented rate.
For economic as well as defence and moral reasons, a Scottish Defence Review would surely conclude that imposing a new generation of Trident nuclear weapons in Scotland in these circumstances – against the expressed view of Scotland's Parliament, as well as a majority of Scottish Westminster MPs – is literally indefensible. Certainly, the people of Scotland oppose the direction of UK defence policy.
Special YouGov polling commissioned by the SNP shows two-thirds of Scots support a Scottish Defence Review.
A majority of more than two-to-one opposes defence personnel and bases in Scotland being run down, and more than three-quarters believe Scottish military regiments should be based in Scotland wherever possible.
People in Scotland support our armed forces, and are proud of the nation's military tradition. It is those UK politicians responsible for the decrease in jobs, the overstretch, and the under-equipping of our brave servicemen and women they object to.
In my view, the analysis of a Scottish Defence Review would demonstrate the modern benefits and opportunities offered by independence.
First, having full responsibilities for defence matters would ensure Scotland as a democratic society could choose which theatres to be involved in. Like other small independent nations, wherever and whenever we did wish to take part in conflict or peacekeeping roles, we would do so in partnership with our friends and allies. And where we judged the use of force to be unjustified, we would have the ability to stand aside.
For example, the 1991 Gulf War involved more than 30 coalition nations acting under the authority of a specific UN Security Council Resolution – including Denmark, Norway, Belgium, Portugal and New Zealand. By contrast an independent Scotland would have been free to decline to take part in the recent Gulf War, based on its lack of a legal mandate.
Second, we would be in a position to ensure the removal of nuclear weapons from Scotland. The UK parties may well be starting to think in terms of moving from four Trident submarines to three, but Scotland's interests lie in there being no Trident stationed in Scottish waters. No independent nation of five million has nuclear weapons, and nor should we.
And third, the perceived disadvantages of independence are no more than chimeras in the modern world. On the basis of mutual interest, it is perfectly possible to envisage circumstances in which we share basing, procurement and training facilities with the rest of the present UK – our foremost friend and ally under all constitutional arrangements – in exactly the same way as defence co-operation exists across Scandinavia.
In such a manner, we can develop a defence policy that is right for Scotland, and is a force for good in our changing world.
Angus Robertson MP is SNP Westminster leader and spokesman on defence and foreign affairs.