The constituents of the European Union find that they can check out any time they like, but they can never leave.
The difficulty of Brexit is the case for Brexit.
The argument against the continued submersion of the United Kingdom within the European Union is that it would constitute an indenture on British sovereignty, liberty, and democracy. That is obviously — obvious now, at least — a fact, and one need not take it as a moral judgment upon Brussels or the European project to acknowledge the fact.
The European Union indentures British sovereignty in the same way it indentures the sovereignty of its other member states, although the United Kingdom wisely arranged to keep control over its own monetary policy. The merging of sovereignties, which necessitates the subordinating of sovereignties, is the point of the European Union, its raison d’être. Again, that need not be understood as nefarious. All international agreements, whether bilateral or multilateral, do that.
But compare the British experience in the European Union with the U.S. experience in NAFTA. A European Union that was a kind of grand Continental NAFTA would have been preferable to and much more practical than a political union creating a half-baked United States of Europe, but set that aside for the moment. When the United States decided that NAFTA as it was no longer served U.S. interests, it had the choice of opening the treaty up for renegotiation or exiting it. (The Trump administration, demonstrating its usual discipline, has so far failed to secure the ratification of USMCA, the successor to NAFTA.) The other NAFTA countries enjoyed the same right of exit. Maintaining the right of exit is the difference between using sovereignty and losing sovereignty.
When the people of the United Kingdom voted to leave the European Union — rightly or wrongly, intelligently or meat-headedly, however you see it — that should have been that. But British sovereignty has become so entangled in European protocols as to render Brexit difficult if not quite impossible without the cooperation of the European Union itself. And that cooperation has not been exactly forthcoming. Brussels has worked to make Brexit as difficult, painful, and expensive for the United Kingdom as it can. It has even gone so far as to demand the creation of what amounts to a national border for goods within the United Kingdom, in effect permanently ceding a portion of British sovereignty to the European Union.
And that is the way in which the European Union indentures British liberty and democracy. There is more to liberty than simple unrestricted freedom of action. Liberty includes rights embedded in a particular political regime and legal context, meaning liberty under British government and British law of British making. The British people might legitimately have chosen another course of action — but they did not. And while majoritarian democracy is an instrument of limited legitimacy and applicability (which is why we Americans have a Bill of Rights — “unalienable rights” cannot be voted away), when a question is put to the people, either the result must stand or the people must conclude that they no longer enjoy sovereignty, liberty, or democracy.
The European Union is not the sort of repressive machine that might be described as “Orwellian.” It is more Kafkaesque, a Hotel California of a superstate whose constituents can check out any time they like but — ask Boris Johnson — they can never leave. That it is the British government currently begging Brussels for a delay does not change the character of that relationship, though of course the incompetence and stupidity of the British government must be taken into account.
The United Kingdom is now set to go through another election in an attempt to settle a question that should have been, in principle, settled by an election back in 2016. That the United Kingdom is finding Brexit so difficult to get done is the best argument there is for getting it done.