The United Kingdom is falling apart. And nobody seems to have really noticed. It’s not the riots and the burning buildings, nor the stumbling stock markets. Those fill every front page.

At a slower, less alarming pace, something more profound is happening: The United Kingdom may well be on the verge of breaking up; actually disuniting its disparate parts.

The word “secession” conjures up images of splinter groups, fringe corners of far-flung states agitating for the independence of their often imaginary fiefdoms: Bomb blasts in the Basque region; guns in Grozny.

But in generally less dramatic fashion, Scotland has voted for a Scottish National Party (SNP) government, committed to an independence referendum; a long-cherished dream. Signs of a rift were also on display when Scottish First Minister Alex Salmond complained bitterly about broadcasters heading coverage of the riots as "UK riots" when they were, in fact, English ones alone. Claiming the footage would damage Scotland's reputation as a tourism destination, he told BBC Radio Scotland: "We know we have a different society in Scotland, and one of my frustrations was to see this being described on BBC television and Sky as riots in the UK."

But the friction and current constitutional confusion between the two countries harks back much further, to the Jacobite uprisings of the 18th century; the Culloden massacre and 1747 Act of Proscription, a law that banned the wearing of traditional dress, use of Gaelic, bearing of arms or even enjoyment of traditional music in an attempt by the British government to pacify the “unruly” Scottish clans.

It was a process that author Alastair MacIntosh describes as the final internal colonization of the British Isles; one that saw some half a million people forced off their land in what became known as the Highland Clearances, while remaining clan chiefs were incorporated into the British ...