In 2014, the people of Scotland will be asked whether their country should become independent. A “yes” response will have dramatic consequences for the defense of the British Isles.

Since 1707, Scotland has been a part of the United Kingdom and has almost always been governed centrally from London. But the creation of a devolved government in 1999 and the 2011 swearing in of a nationalist administration has accelerated the march to independence. Under Scottish National Party (SNP) plans, an independent Scotland would keep sterling as its currency—at least initially—and retain the queen as its head of state. Though a close relationship with England seems solid, defense remains something of a sticking point.

Since the 1960s, the U.K.'s submarine-based nuclear deterrent has been situated on the highly guarded Faslane Naval Base. Four Vanguard-class submarines, each capable of carrying 16 Trident submarine-launched ballistic missiles, maintain a constant vigil. But the SNP has a rigorous non-nuclear weapons policy and wants the Trident system withdrawn as early as possible.

This could prove precarious, because “unlike most nuclear powers, the U.K. has just one single delivery method for its nuclear weapons,” says Prof. Malcolm Chalmers, an expert on U.K. defense policy at the Royal United Services Institute think tank. “If it wanted to be belligerent, an independent Scotland could demand the removal of Trident and the U.K. would have no choice but to unilaterally disarm, because there is no alternative [site to house the subs].

“If we still had an airborne nuclear deterrent . . .we would have simply moved the aircraft and the weapons to another base in England, but the infrastructure for these submarines has been built up over time to very specific standards . . . ,” adds Chalmers. It would take more than a decade to recreate the infrastructure, he says.

Such a “radical” move is unlikely, as it would upset NATO and European Union members. Until October 2012, the SNP was anti-NATO because it felt the organization was a “nuclear weapons-based alliance,” but the party now feels it could be a member of NATO's “Partnership for Peace” program.

Chalmers believes that Scotland will take a cautious approach, urging that the nuclear weapons be moved at London's earliest convenience. That might make some Scots unhappy, but at least they will no longer be paying for the system or the multibillion-pound program that will eventually replace it.

But others are concerned that the country's small but important defense industry could move to the U.K. as well. Shipbuilding, which employs 5,000 people in Scotland, would be most at risk, particularly as current British government policy is to produce ships and submarines for the Royal Navy using national industry. Much of this capacity is in Scotland, but in the event of independence it is likely that military vessel manufacturers would exit.

The U.K. would also likely move its 15,000 employees south of the border, along with four Army infantry battalions, two Royal Marine Commando units and five squadrons of Tornado and Typhoon fighter aircraft.

Scotland will then need to consider its own defense. Government ministers have already disclosed that a Scottish defense budget would be around £2.5 billion a year ($3.9 billion), enough, according to Chalmers, for a defense force larger than that of Ireland but—as a proportion of GDP—around the same as the smaller Scandinavian countries. Scotland has significant interests to look after. Many of its exports come from North Sea oil, so capabilities will have to be created to patrol the oil and gas fields, and capabilities must be put in place to deal with cyberwarfare and counter-terrorism.

“There would not be much point in Scotland inheriting equipment and assets from the U.K. because the U.K. armed forces have now been structured for deployment overseas. . . . [Creating a] new military from scratch will not be easy. Significant one-off costs will also be involved,” adds Chalmers.

There are also questions about the make-up of a Scottish armed force. Would it comprise an entirely fresh pool of Scottish citizens? But then, exactly who is a Scottish citizen? Currently, nearly 800,000 Scotland-born people live elsewhere in the U.K. and will not be able to vote in the referendum. Yet, 400,000 denizens who were born outside Scotland but now reside there—can.

Recent opinion polls suggest enthusiasm for Scottish independence has slumped somewhat. Approximately 23% are saying they would vote “yes,” so it is perhaps no wonder that government departments are spending more time studying how to urge Scots to say “nay” rather than planning for an affirmative outcome.

The Scottish government is planning to hold its referendum in fall 2014, and if the people green-light the idea, it is the administration's intention is to have a constitutional platform in place for Scotland to become independent by March 2016.