LONDON — Britain will go it alone — turning its back on decades of integration to control its own borders and free itself from the European Union's spider web of rules and regulations.
It is a bold and risky move for this proud island nation. Few countries have walked away from such a large, prosperous and peaceful alliance in favour of a solo path.
The impact on Europe will be momentous — and won't be clear for several years at least. Britain's action comes at a time of maximum peril for the EU, which finds its liberal founding principles under pressure as never before. With one brisk step, Britain has ended the EU's growth phase and, perhaps, started it on a path of decay and possible dissolution.
It's impossible to know if Britain will be the only disgruntled nation to walk away, or if it has set in motion a process that others will follow, leaving the European dream of an "ever closer union" nothing more than a quaint catchphrase from an era gone by.
Until the last few years, which have been marked by financial and immigration crises, there seemed to be a certain historical inevitability to the expansion of the European Union.
It grew from the rubble of World War II, binding together former enemies whose common history was marred by centuries of bloody warfare.
Most importantly, it represented a triumphant vision: The countries that beat back Nazism and fascism would extend a hand to Germany and Italy, where those ideologies had flourished, and pull them into the modern world while the destroyed continent was rebuilt.
United against a common Soviet enemy, and backed by the considerable firepower of the United States via the NATO alliance, the Western European nations that formed the EU — first as an economic bloc called the European Economic Community — prospered under remarkably liberal trade and immigration policies.
Symbols of union abounded: The British and French co-operated to build a formidable Channel Tunnel that forever linked the two nations. Most countries jettisoned their national currency (and a bit of their sovereignty) in favour of the euro, and physical border crossings were dismantled. National boundaries, once so bitterly contested, seemed like hypothetical lines drawn on a quaint, obsolete map.
When the Soviet Union collapsed in 1991, and its Eastern European satellites were finally set free from Kremlin control, it seemed only natural that the leaders of the newly liberated countries would look to France, Germany, Britain and other Western powers for inspiration.
They had endured stifling dictatorship, brutal secret police abuses and precious few political rights. The allure of the prosperous West, with its free press, open markets and expanding economies, seemed irresistible.
So the union grew, moving beyond its core in Western Europe to the edge of the Black Sea.
Hearty, triumphalist figures like Germany's Helmut Kohl and France's Francois Mitterrand helped engineer the unification of East and West Germany and welcomed Eastern European newcomers, setting in motion policies that eventually led the EU to expand to an unwieldy bloc of 28 nations.
It was a magnanimous vision — possible perhaps only in a time of sustained economic growth — and it tied wealthy countries like Britain and the Netherlands to distant, poorer lands that shared little in terms of common language or traditions.
The optimistic mid-1990s blueprint, backed by handsome subsidies for the newer members, was based on the belief that countries like Poland and Slovakia would develop into democracies like Germany and France — with free trade and the free movement of people helping to bring about this profound transformation.
The situation today is dramatically different. The single currency known as the euro — never adopted by Britain — has faltered badly, emphasizing the splits between wealthy countries and indebted nations like Greece. Europe has been taxed by the unplanned arrival of well over 1 million immigrants fleeing warfare and poverty in the Middle East and Africa, and Islamic communities have come under rhetorical fire in some countries following major extremist terror attacks in Paris, Brussels, London and Madrid.
The chaos has led to a reversal of sorts in Eastern Europe, with some leaders rejecting the free movement of people, and to well-grounded fears in Western Europe that right-wing leaders hostile to the EU are gaining ground in France, Germany and other countries as well.
Now Scotland, unwilling to be dragged out of the EU without a fight, is setting in motion a second independence referendum that would split it off from the United Kingdom.
Britain's withdrawal must be seen in this context.
Prime Minister Theresa May's invocation of the brief Article 50 clause —which its architects believed would likely never be used — curtails the Utopian vision that 28 disparate countries can find common cause that trumps nationalistic concerns. It comes as the EU's liberal principles are quickly falling out of vogue.
The tests will come quickly now. There will be a presidential vote in April in France, where far-right candidate Marine Le Pen, strongly opposed to the EU and its currency, looks formidable. Vital German elections are set for September.
The external situation facing the EU has changed beyond all recognition. The friendly Russia that took baby steps toward democratic freedoms after the Soviet era has vanished, replaced by President Vladimir Putin's hard-line approach. And the United States, long the rich, benevolent uncle in this relationship, is now led by President Donald Trump, who as a candidate urged Britons to break free of the EU and its rules.
The future is impossible to know, but the start of Article 50 proceedings puts a merciful end to Britain's ambivalent relations with the EU bloc after decades of indecision.
Now Britain — no longer imperial, and perhaps to be shorn of Scotland as well — will stand apart once more.
Gregory Katz, The Associated Press