It turns out there really is an independence movement in the Shetland Islands. In response to Friday’s post, a reader sent me a Wall Street Journal article on the efforts of the Shetlands, Orkneys and Outer Hebrides, those beautifully wild islands in the North Sea, to hold their own referendum on secession from Scotland. The parliamentarians in Edinburgh, perhaps with an eye to the islanders’ claims to waters rich in fish and oil, denied the request. Which raises a question: Is there an ideal size and composition of a country and what’s the best way to achieve it?

These days, some very bad guys are expanding their borders by naked force. Vladimir Putin feigns innocence as he moves baldly into eastern Europe; ISIS uses terror to extend its caliphate in Mesopotamia. The Scots, by contrast, voted peacefully on independence, lost and went back to work. But secession movements have rarely been so civilized and have almost never been decided by vote. The United States fought the deadliest war in its history to keep the union intact (and force an end to slavery); the bloody “troubles” in Northern Island has been “the longest major campaign in the history of the British Army.”

Nationalism arose to combat the sectarian violence of warring tribes, but it rarely honored the unique cultures of its people, demanding instead capitulation to a centralized state. Whatever your position on last week’s referendum, it was an extraordinary effort to accommodate peacefully the conflicting demands of nationalism and diversity.