The Commons Defence Committee has been harrumphing about the SNP's defence plans for an independent Scotland. Apparently, the proposed budget of £2.5 billion would not be sufficient to provide a credible airforce, submarines, a fully-equipped surface fleet, or create its own intelligence systems (that GCHQ shit is seriously expensive). The committee has also warned that moving the Trident nuclear fleet to a new base outside Scotland would take years and cost billions of pounds (who'da guessed?)
The Scottish plans are light on detail, though presumably kilts will be involved, but I think they're missing a massive opportunity to advance the cause of independence. Their problem is that they are approaching the question the wrong way round. Rather than start with a threat analysis, i.e figure out what you need to defend against, they have started by considering what a suitable amount of money would be relative to current expenditure (i.e. incremental as opposed to zero-based budgeting).
The total annual UK defence budget is about £36 billion (excluding foreign aid), of which Scotland contributes about £3.3 billion through taxation. However, it is estimated that only £2 billion of that latter amount is spent in Scotland, so it is assumed that the future budget should be somewhere between the two figures. The other datum they have thrown into the calculation is the defence budget of the country they think would be their closest comparator as an independent nation, Denmark. The Danes currently spend about £2.6 billion (DKK 23 billion). These two factors combined produce the finger-in-the-air estimate of £2.5 billion for Scotland's defence.
Menzies Campbell's claim that the SNP's sums were "done on the back of an envelope" is close to the truth, however he, together with the other unionist critics, is guilty of a different error, which is to assume that Scotland needs a mini-version of the UK's defence establishment, sans Trident. Let's try and approach this more logically by first considering the threats that an independent Scotland might conceivably have to face.
If we assume that Scotland as an entity stems from the Kingdom of Alba around 900, after the end of the Norse raids, then the only persistent threat to Scottish territorial integrity up to the union in 1707 came from England. Everyone has been too polite to point this out so far, perhaps because of the 500th anniversary of Flodden Field, when the roles were for once reversed. Of course, it's improbable that England would ever threaten an independent Scotland with invasion again (though you could imagine a future in which Boris Johnson PM rattles his sabre), but to be on the safe side, it is estimated that it would cost about £400 million to rebuild Hadrian's Wall. This is not an entirely facetious observation.
At about 90 miles, a wall between Berwick and the Solway Firth would be longer than the 73 miles between Wallsend and Bowness, but using modern materials, rather than replicating Roman stonework, it would be cheaper to build per mile, so the net cost is probably in the same region. For comparison, the 165 mile border fence between Israel and Egypt in Sinai is expected to cost somewhere around £500 to 700 million (NIS 3-4 billion) once completed.
Of course, a wall alone would not be an effective defence, and (assuming good neighbourly relations) could be an impediment to trade (though future fiscal policy could give rise to smuggling, which a wall might help control), but it does suggest that an annual defence budget of £2.5 billion would be more than adequate to counter the threat of invasion from the South. The lesson of history (certainly Scottish history, see messrs Wallace and Bruce) is that effective defence depends on an ability to raise a militia (blue face-paint optional), with the regular armed forces serving to hold up an invasion and buy time for full mobilisation. Switzerland is a good example of this approach, having an active force (95% part-time) of about 130,000 troops on a budget of £3 billion, which compares with the UK's active force of about 200,000 (full-time), plus 180,000 reservists, on ten times that amount.
Beyond England, and leaving aside stateless or domestic threats, the nearest territorial rivals to Scotland would be Norway, Iceland, The Faroe Islands (under Danish sovereignty), and the Republic of Ireland. There is obviously the potential for a new Cod War, or perhaps disputes over North Sea or West of Shetland oil and gas, but the odds look pretty slim, not least because of the calmative effect of NATO and the EU. A large standing army typically exists to project state power beyond national borders - i.e. its purpose is invasion rather than defence. Assuming an independent Scotland would not be casting envious eyes at the Faroe Islands (some of their footballers are quite useful), a small professional army coupled with part-time territorials looks appropriate.
Denmark's budget is clearly driven by regional considerations. For them, invasion from the South is a credible threat. Though relations are now good, and a bellicose Germany looks unlikely any time soon, the fact that they were invaded 73 years ago (and at 2 hours it was the briefest military campaign on record) means they remain cautious, if not exactly jumpy. The other consideration is Denmark's strategic position at the entrance to the Baltic, which means they could be dragged into wider strife involving other Scandinavian and Baltic states, not to mention Russia. In other words, Denmark faces more obvious threats than Scotland, and greater scope for being in the way of someone else's aggression.
In fact, it may make sense to also consider Iceland as a comparator for Scotland. As the only member of NATO without a standing army (they have 200 peace-keepers, plus a coastguard of 4 vessels and 4 aircraft), they are obviously at the other extreme to Denmark. Their total annual defence budget is a minuscule £8 million. It's improbable an independent Scotland would ever go this far, if only because popular sentiment would demand the maintenance of historic units like the Black Watch, as well as retention of various naval bases and airfields that provide domestic employment, but it does suggest that a credible defence force could be mobilised for significantly less than £2.5 billion a year.
It should also be borne in mind that the cost of moving the Faslane and Coulport Trident facilities to Cumbria (Northern Ireland would be ruled out for obvious reasons) would not be a problem for Scotland, it would be a problem for the rump UK. Indeed, an astute politician would charge the UK a hefty rent to maintain the bases for a decade or two (Scottish nationalists would surely accept their temporary presence as the price of independence), which would defray a large part of the Scottish defence cost.
The point about all this lunacy is that it reveals a few sordid truths: that defence spending has morphed into subventions to depressed areas of the country; that defence capability is determined by political posturing; and that the amount of money we spend on defence is ultimately arbitrary, owing more to special interests than actual need.
If Scotland could get by with a defence budget of £2 billion (and I have no doubt that it could), then the UK as a whole could certainly get by on £20 billion, which would put us on a par with Italy, Brazil and South Korea (and probably Israel, who officially spend about £9 billion a year but have an "off budget" nuclear programme, not to mention hefty US subsidies). We could halve our defence spend without adversely affecting our security, though our ability to intervene abroad would be reduced (this might be a blessing in disguise).
The Scots should be ridiculing defence expenditure as waste driven by English post-imperial delusion, rather than trying to explain how they'll afford the latest in fighter jets and submarines on a "paltry" £2.5 billion, but the cry of "defence jobs" is too emotive. At least they're not proposing a wee aircraft carrier, to be named Braveheart.