Scottish independence vote: It's not all about the Scots

As Scots head to the polls today, their vote for or against independence will be local – what choice will improve their education and job prospects and bolster their savings accounts.

But their ballots will resonate far beyond Glasgow’s homes and highland farms. A “Yes” vote for independence will have a resounding effect on the United Kingdom and its place in the global order.

SPECIAL REPORT: Whither Great Britain after Scottish vote?

That’s one reason that British Prime Minister David Cameron has feverishly urged Scots to stick with the centuries-old union leading into a vote that polls have shown too tight to call. It's also behind such dramatic headlines today as that in The Times of London, which printed the Union Jack on its front page with the headline: “D-Day for the Union.”

There is so much at stake – starting with Mr. Cameron’s own legacy – that it’s hard to choose what counts most. But here are three key ramifications that could be felt around the world:

1. DEFENSE. Just as the UK would lose 10 percent of its population if Scotland were to leave, so too would it lose manpower in the British armed forces. Britain is barely maintaining its defense spending goals, and near-constant cuts mean every pound – and person – counts. But the most significant defense issue is Britain's nuclear deterrent. Scotland is home to four submarines armed with Trident nuclear warheads, and Scottish nationalist leaders have promised to make Scotland nuclear-free within four years. That would leave England scrambling to find a new home for the arsenal – and if it couldn't, the UK could become the only permanent member of the UN Security Council without a nuclear deterrent.

2. EUROPEAN UNION. Even as Scots consider leaving the United Kingdom, the United Kingdom is considering leaving the European Union. If Scotland leaves, it makes it more likely that the in/out referendum being considered for 2017 in Britain will end with an "out" vote. Euroskepticism is much stronger in England than it is in Scotland. In fact, one doubt that has hung over the Scottish nationalist campaign is whether Scotland can quickly regain EU membership. If the United Kingdom ends up outside the European Union, the balance of power within the entire bloc will have to be recalibrated. 

3. BRITISH PRESTIGE.  For the US and the West overall, Britain's voice has counted among the most convincing on issues ranging from Islamic terrorism to economic reform. But  the break-up of the United Kingdom and then potentially its own divorce from the EU would likely result in a nation looking inward at a time of increasing integration. “It has the potential to be almost a ‘Suez moment’ all over again, where Britain in terms of its foreign role really becomes quite introspective,” says Daniel Kenealy, a public policy and EU expert at the University of Edinburgh. “It may be able to pay less attention to the world as it has to pay attention to itself as it manages this breakup.”