As Others See Us: The View from Ireland

Because nobody - really, nobody - is seriously considering the prospect of such a war.

But it is something at least one international military planner is imagining - albeit fleetingly - as he thinks through the consequences of Britain's potential break-up.

Dorcha Lee is one of Ireland's most respected soldiers, a veteran blue helmet of UN peacekeeping operations in the world's hotspots. He admits a cross-border conflict between Scotland and whatever the rest of the UK becomes is a "uncomfortable scenario".

But Scotland, the retired colonel reckons, should address "the academic possibility of uninvited military action from the South" as it plans its defences.

His own country, after all, has had to think this issue through.

I don't want to overstate Lee's thinking on an attack from a rump UK. After all, Lee doesn't think it likely at all. "I mainly mention the possibly of military aggression from the South to dismiss it," he said.

What is interesting is that - free of the baggage of Scottish politics - the soldier turned thinker has imagined such a scenario at all.

His - albeit very slim - concern? That an northern intervention might come if Scotland neglected its defences when England was at war.

After all, the neutral Republic of Ireland - back during World War II, feared its ports would be seized by Britain to prevent them being used as a back door to London. They weren't.

Lee said: "Scotland will, most likely, have to give assurances to the UK that it would not be used by a potential enemy to attack the UK.

"The new state will have to have the military means to back up these assurances. This will apply whether Scotland is a member of NATO or not."

Is this scenario far-fetched? Yes. But the future lasts a very long time. And one unionist-minded politician has raised the issue - if, let's be honest, only to scaremonger.

Last year Lord Fraser of Carmyllie, a former Tory minister, said an English airforce may have no choice but to "bomb the hell out of Glasgow and Edinburgh airports" if it looked like they could fall in to the hands of one of London's enemies.

I am not going to pretend to know what sort of defences any independent Scottish state should have.

Right now Better Together will happily tell any journalist who asks that defence is one of their strong points.

Scots - unionist campaigers reckon - are worried about whether their country could put up a fight on their own.

Is it fair to say the SNP response has been to talk up the prospect of arming an independent Scotland to the teeth? Dunno.

But Angus Robertson, the party's defence spokesman, cites Nordic levels of defence spending. And, for "Nordic", read "high".

Now over in Ireland - where they spend proportionately less on defence than any other nation in the EU bar Luxembourg - Lee has a different take.

The expert said: "Freed from the need to contribute to UK's strategic military commitments, Scotland can reduce its military spending very substantially, to the new state's economic advantage.

"Overall, I believe that the options on the defence issue will support the case for a 'Yes' vote in the Referendum."

Lee - in a paper published in the Sunday Herald last weekend - suggested Scotland should spend around 1.1% of its gross domestic product on defence, about the same as Belgium and far lower than the UK's 2.6% or a figure of 1.7% pencilled in by nationalist strategists.

What does Ireland spend? About 0.6% of GDP. So Lee isn't suggesting Scotland should copy his own country. Indeed, military sources have suggest such a scenario would cause resentment in London, as if Scotland was essentially hiding behind British defences without contributing to their costs. Oh - and very theoretically - putting itself at risk of having its airports "bombed to hell" in case they are used as landing strips by hypothetical enemies.

I'll be writing on more Irish views of Scottish independence again very very soon.

In the meantime, don't take my word on what Lee is saying about Scottish defence. Read his latest paper on the subject:

Dorcha Lee: Defending Scotland the Brave.

When the Scottish people go to the polls next year to vote in the independence referendum, they will also be deciding the future shape of Scottish Defence.

In the event of a Yes vote, an independent Scotland would need to develop its own Defence Forces, to assure its freedom, under line its sovereignty, and provide a secure environment for its people to live and prosper.

Freed from the need to contribute to UK's strategic military commitments, Scotland can reduce its military spending very substantially, to the new state's economic advantage.

Overall, I believe that the options on the defence issue will support the case for a Yes vote in the referendum.

The SNP has produced a viable outline Defence Policy, which is a good starting point for the debate.

It is, however, important, that the widest possible range of options, including dissenting arguments, be openly discussed.

The implications of these options should be fully identified, and made available to the electorate.

In the long term, the more information in the public domain, the better. As we in Ireland know too well, referenda have been lost by governments' failure to fully communicate with the electorate. On the defence issue, debate should be encouraged on all the implications involved, including on uncomfortable issues, such as on a threat analysis, and options on possible defence arrangements with the UK.

Continuity is a recurrent theme in the SNP's approach to arguing the case for a Yes vote. This makes sense politically. The Scots are a cautious people, not prone to making great leaps in the dark. As it is, they will need strong convincing, in the first place, to support such a radical proposal as independence.

Nevertheless, continuity in the Defence area, could lead to a dysfunctional Scottish Defence Force (SDF), if the military assets being retained are not fit for purpose. The new SDF should be designed, organised and equipped, to fulfil the roles envisaged.

In any threat analysis, the possibility of a conventional attack on Scotland, at the present time, lies somewhere between nil and zero.

Nevertheless, within the past hundred years, Scotland has been a belligerent in two world wars, and, during the Cold War, under the shadow of nuclear attack due, in part, to the presence of nuclear weapons based at Faslane.

The lessons of history have taught us that situations do change, and, in the long term, Scotland could, in the future, be caught up in a conflict between superpowers, not of its own making. Scotland will need to have a military capability to protect its present, and future, offshore assets, not to mention new shipping lanes resulting from the melting of the Arctic icecap.

An Independent Scotland will, most likely, have to give assurances to UK that its land, sea and airspace, will not be used by a potential enemy to attack the UK. The new state will have to have the military means to back up these assurances. This will apply whether Scotland is a member of NATO or not.

In considering any threat to Scotland's independence, and no matter how unlikely, it is also necessary, academically, to address the possibility of uninvited, post-independence, military action from the South.

One scenario would be, if Scotland neglected its defences, to the extent that the UK was at risk of attack by an enemy using, for example, Scottish air space.

However, I mention the possibly of military aggression from the South, mainly to dismiss it. I am sure a UK that will accept Scottish Independence in the first place, will not wish to overturn this step by use of military action. Nevertheless, I note that some fringe nationalist groups in Scotland, see this scenario, and are advocating a very strong military posture by Scotland, including conscription.

As regards a possible future threat from the UK, Scotland can be reassured by lessons from history. In the 1921 Treaty between UK and the Irish Free State, defence related assurances were given by both sides, and were honoured when put to the test, during WW2. Contrary to wartime rumours in the UK, the Free State did not give logistical support to the German Atlantic U- Boat fleet. The UK respected Irish Neutrality, and did not try to retake the vital ports they handed back in 1938, even though the UK's very survival was at stake.

In my view, the most likely scenario is that Scotland and the UK will stand together in any future conflict that threatens these islands.( I use the term "these islands", advisedly, as, in the event of Scottish Independence, the term "British Isles", (which raises the ire of many Irish), will finally be redundant!

Perhaps they could be renamed the "Anglo- Celtic Isles"?

International terrorism is a threat to all nations including Scotland. While the police are in the front line for dealing with all serious crime, including terrorism, the new SDF will need to be able to support the police in situations beyond normal police capabilities.

In this role, the SDF will have to be ready to carry out a wide range of tasks, including bomb/IED (improvised explosive devices) disposal, and the protection of vital installations such as the seat of government, and oil and gas rigs.

The police may require military assistance to deal with criminality and even home grown terrorism, in situations ranging from, for example, interception of maritime drug running, to armed support for the police in the event of subversive activity.

Such subversive activity could come from the regions of Scotland opposed to breaking the link with the UK.

Not everyone may accept the majority decision, and some might be prepared to use force, and seek a partitionist solution, as happened in Ireland.

The SDF will have a range of assets which could be made available to the civil authority for emergency situations, natural or man-made, which threaten the lives of people or property. The options on whether the Search and Rescue (SARS) services should be provided by the SDF or civilian contract, or a mixture of both, need to be examined. If SARS is to be provided by the SDF it should not have to compete for funding within a military budget system. The RNLI service should be continued as it did in Ireland.

An independent Scotland, with a professional, well trained and a well-equipped, SDF, will be a welcome addition to any international peacekeeping mission. Such involvement is greatly appreciated by the international community.

It will enhance Scottish Foreign Policy, and be a great source of national pride. The presence of SDF units in UN, and other, peacekeeping missions , will be a potent symbol that Scotland has truly taken its place among the nations of the world.

An independent Scotland, and the UK, will have much to gain by negotiating defence arrangements that protect the vital interests of both countries. However, if possible, it would also be helpful, to identify the scope, and parameters, of any such negotiations, before the Referendum takes place. Again, keeping the electorate as fully informed as possible is a paramount consideration.

Finally, I believe that, with more research and discussion, the many questions raised about the defence of a future independent Scotland can be satisfactorily answered. The answers lie, in part, in studying how other small nations address this issue, not just in Denmark, which has already been cited, but also in Ireland.

Scotland does not have to reinvent the wheel.