Give the Scots and the English credit for settling a long-running debate over their relationship — they’re doing it in the most amicable manner possible. Unlike other recent plebescites on independence — such as the mockery in Crimea earlier this year — this referendum in Scotland has been recognized as legitimate on both sides, with both sides agreeing to abide by its results, and isn’t taking place under a military occupation, either. Even so, the UK, the EU, and the West as a whole are casting a nervous eye on the vote taking place today, as the implications of a Scots-English divorce are still mainly unknown:

Scotland voted in a referendum on Thursday to choose whether to end the 307-year-old union with England and become an independent nation or stay within the United Kingdom – a decision which could have consequences across the globe.

From remote highlands and islands to the tough city estates of Glasgow, people were almost equally divided over a vote watched closely by Britain’s allies, investors and restive regions at home and abroad.

Pre-voting opinion polls gave the “No” campaign – those in favor of remaining in the United Kingdom – a slight edge. But hundreds of thousands of people still making up their minds held the key as polling stations opened. …

The independence movement says Scots should be able to choose their own leaders and make their own decisions rather than be ruled from London. Supporters of the union say Scotland is more prosperous and secure as part of the United Kingdom and the ties that bind its peoples are too tight to be undone.

It’s difficult to discount the desire to control one’s own destiny. The Scots tied themselves to the more prosperous and populous British centuries ago, and feel as though they have had little say in governance ever since. Over the last couple of decades, Scotland has been granted more autonomy in the so-called devolution of powers, but the decision by Tony Blair to join the US in the Iraq War — a move opposed by Scots — demonstrated for many the limits of British federalism. Not surprisingly, that decision has played a significant part of this debate, along with the commitment to the National Health Service and the strong support for the Labour Party agenda in an era of Tory rule in London.

But just how much would Scotland control its own destiny if it votes to split from the UK? It would have to take on a proportional share of the UK’s national debt, and its only two realistic choices for currency would be the English pound or the euro. Both would hand control of monetary policy to an outside power, and joining the euro would also force Scotland to abide by budgetary constraints that might make British sovereignty look generous. As members of the UK, Scotland now has at least some influence over Parliament in London, and therefore monetary and budget policy there, an influence it will lose after independence. In that sense, the referendum looks a little like cutting off one’s nose to spite one’s face.

Still, these decisions are not always based on ledgers and specific policies. The desire for self-rule sets deep within the human heart, as we Americans know. Perhaps our own independence looked just as questionable in 1776 in terms of global influence and fiscal prudence. (Then again, the American colonists had no representation in Parliament at that time, which was one of the main issues in attempting to settle the hostilities once they arose.) The problem for Scotland will be a successful but close No vote, because once this question achieves legitimacy, it will never go away. Activists for independence will not accept a narrow defeat as a definitive answer, but will bring it back again and again until it passes, in large part because of that all-too-familiar desire for self-determination.

If it succeeds, don’t expect the impulse to be limited to the Scots, either:

As the world waits to see how Scotland votes on Thursday, more than a few European regions are watching very closely indeed.

If Scotland chooses independence, many regions with highly organized separatist movements like the Catalans in Spain and the Flemish in Belgium will be bolstered in their own fight for autonomy. Others where the aspiration to separate faded after generations of frustration, like the Breton independence movement, or Padania in northern Italy, may now take heart. Even if Scotland chooses to remain part of the United Kingdom, these regions will be watching closely to see what concessions the Scots earned by staying, and just how valuable the threat of a vote might be.

In one sense, the umbrella of the European Union may be accelerating the legitimacy of these movements. As long as we belong to Europe, the argument may go, why do we need to belong to Britain/Spain/France/Italy?