It is not hard to be pretty dismissive of Belgium. As a country it has offered little to the wider world beyond its sickly beer and sicklier chocolate (plus Tintin, to be charitable). Now it appears to be engaged in one of its regular bouts of fratricidal introspection. Never mind “name five famous Belgians”, discovering five of them who like each other seems to be a challenge. As The Times reported on Saturday, there has been no proper national government there for three months and it is being seriously asked whether the place should be split between Flanders and Wallonia, with Brussels becoming a kind of Washington DC for the EU. So it could be Belgium RIP. Will anybody notice?

Before we scoff, it is worth wondering whether the United Kingdom is destined to share the fate of Belgium, though at the same time barely recognising its own misfortune.

Within the space of a few weeks this year an administration was formed in Northern Ireland that contains Sinn Fein, a party committed to removing Ulster from the UK and merging it with the Republic of Ireland. Soon afterwards the SNP, a party whose purpose is to release Scotland from the UK, was sworn in to head the executive in Edinburgh. Not long after that Labour was compelled to accept a coalition arrangement in Wales with Plaid Cymru, a party with independence as its ultimate objective. If this were a foreign land, these developments would be reported as the death rattle of a nation.

Of the three events, the rise of the SNP is unquestionably the most significant. It is in charge of an administration (albeit a minority one) rather than being a mere junior partner, as are Sinn Fein and Plaid Cymru. Polls in Scotland, furthermore, indicate that – while there is not, at present, a majority for an outright divorce from the UK – there is strong support for a much more open marriage. Alex Salmond, the able, astute and populist First Minister (a sort of Ken McLivingstone but with talent) will not secure a referendum on independence by 2010 as he wants, but if his party is reelected a year after that his mandate for a ballot on Scotland’s future will become undeniable. At the least, his country is likely to emerge as the British equivalent of Quebec; nor is the complete division of Scotland from England – akin to the secession of Slovakia from Czechoslovakia in 1993 – unthinkable. These scenarios can be prevented only if Labour retains office in Britain as a whole – a Tory victory would trigger a stampede for Scottish separation – and regains it once again north of the Border by 2011.

All of which means that the unopposed nomination of Wendy Alexander to lead the Scottish Labour Party on Friday is a moment of underestimated but enormous importance. Ms Alexander is virtually unknown in England yet she is a key player in a party that is less Yes, Minister than Ask the Family. She is the sister of Douglas Alexander, the International Development Secretary, who is chums with Ed Balls, the Children, Schools and Families Secretary, who attends Cabinet with his wife Yvette Cooper, the Housing Minister, both of whom are mates with Ed Miliband, Minister for the Cabinet Office, whose brother is David Miliband, the Foreign Secretary. Looking at all this it is tough to avoid the conclusion that if Labour is defeated at the polls it will be as much because of excessive inbreeding as incompetence.

Yet Wendy, despite being a humble opposition leader in a devolved legislature of limited powers, is about to become more pivotal than Douglas, Ed, Yvette, Ed II or David. It is scarcely an exaggeration to claim that she will be the second-most-important member of the Labour Party for its medium-term future. If she cannot stop Mr Salmond in his tracks, then the impact for Labour will be seismic.

Were Scotland to emulate Quebec, then the English might finally become aware of it and be profoundly resentful of its special status. The demand that Scottish representation be cut in the House of Commons, or that there be “English votes for English laws”, will become louder. That it is an irrational idea (everything that the English-dominated British Parliament does has an effect on Scotland, even in areas such as education and health that are supposedly fully devolved, whereas almost nothing enacted at Holyrood disturbs England) will be irrelevant. The process by which the Conservatives mutate from being “the party of the union” to the “English National Party” would be completed.

If Scotland was to bolt through the exit door as Slovakia did then the consequences would be more explosive. It is possible for Labour to triumph in an election for Westminster without Scottish votes but the task becomes notably harder. It would be like the Democrats attempting to carry a presidential contest without California or the Republicans having to make do without Texas and Florida. And the time at which either the “Quebec” or the “Slovakia” constitutional crisis would loom into sight (2012-2015) would be the point when either Douglas or Ed or Yvette or Ed II or David might be fancying their chances of succeeding Gordon Brown in Downing Street.

But if Ms Alexander fails, then whichever one of them it is may find him or herself having a sudden change of heart about the Westminster electoral system. For if Scottish separation becomes a realistic and imminent prospect, Labour may well adopt proportional representation as its insurance policy. It would be the most plausible device for keeping the party in charge in London while convincing Scotland that it should not impersonate Slovakia. Which variation of PR would be chosen is a matter of conjecture; Labour might go for the d’Hondt method. Its originator, Victor d’Hondt, was appropriately enough a 19th-century lawyer from Belgium.

Times Recommends

• Graveyard of empires could claim more careers
• Would you live on the wrong side of the Berlin Wall?
• At last we’re getting our heads out of the sand