After years of dodging bullets and muddling through, the European Union has taken one in the chest with Britain's referendum vote to leave the prosperous continental club. Worse, the bullet cannot be extracted immediately to enable the body politic to heal swiftly. An open wound will fester for several years of exit negotiations, draining strength the Union needs to recover, and making it more vulnerable to other blows. Brexit is the most visible sign of a wider decline in the ideal of ever closer European integration around the continent, even if the UK was always the least enthusiastic member. The EU, which former British European Commissioner Chris Patten once described as "a wonderful experiment in arguing about fish quotas instead of shooting at each other", is as out of fashion as a double-breasted jacket. National leaders mostly avoid talking about Europe beyond platitudes. Few in Paris, Berlin, Warsaw or The Hague seem willing to contemplate the hard choices that may now be needed to reinvigorate the EU and halt a return of nationalism. It took visiting US President Barack Obama to remind Europeans just how far their continent had come from the ruins of World War Two and what it stands to lose - "one of the greatest political and economic achievements of modern times". "A united Europe - once the dream of a few - remains the hope of the many and a necessity for us all," Obama proclaimed in Hanover, Germany, in April. Yet today's Europeans take peace, open markets and open borders for granted and fret about bureaucracy, immigration, a loss of national identity and remote unaccountable rulers. Symptoms of a backlash against sharing sovereignty include the rise of populist eurosceptic parties in most EU countries but also the inability of founders Germany and France to agree on ways to strengthen the 19-nation single currency at the center of the European project. The British problem was just one of half a dozen crises that together threaten the survival and success of the EU. "To the unkind observer, the EU today may look like an overextended empire with a weak center, aging population and semi-comatose economy, growing internal fragmentation and a world of trouble on its porous borders," says Loukas Tsoukalis, professor of European Integration at Athens University and a former top policy adviser to the European Commission. The euro zone has traversed a painful sovereign debt crisis since 2010 without making monetary union fully sustainable. Most economic literature suggests that requires a common budget and some sort of common safe debt instrument. Germany opposes both. A Greek exit was narrowly avoided last year but Athens' debt problem remains unsolved. Euro area economies continue to diverge with mass unemployment and austerity gripping the south. Growing income inequality in most European societies and resentment in some parts of the west at the impact of the bloc's eastward enlargement since 2004 have fueled public anger. Surfing on hostility to globalization and immigration, populists could deal further blows to European unity in Austria's re-run presidential election and Hungary's referendum on migrant quotas on Oct. 2. The same forces may also unseat the Italian government in a constitutional referendum in the autumn and the Dutch one in a general election early next year. The EU has stemmed for now an influx of more than a million refugees and migrants but failed to share them out across the continent. Moreover, dependence on Turkey as Europe's gatekeeper is increasingly uncomfortable as President Tayyip Erdogan cracks down hard on opponents, the media, judiciary and civil society after a failed July 15 military coup. Islamist militant attacks in France, Belgium and Germany, coming on top of the migration flows, have undermined citizens' faith that a Europe with open internal borders makes them safer. The EU may be reaching the limits of what British thinker and diplomat Robert Cooper calls the "post-modern state". In a 2002 essay, Cooper described Europe as the most developed body politic that did not emphasize sovereignty or the separation of domestic and foreign affairs. That model remains a beacon to many statesmen and business leaders around the world. In Asia, Africa and Latin America, groups of countries seek to emulate EU-style integration, though the Asians remain more wedded to national sovereignty. But on its home turf, post-modern Europe is in deep trouble. The dominant reflex since the British vote has been to emasculate the European Commission, the unloved "honest broker" at the center of the EU system, sideline the European Parliament and hand more power back to national governments and lawmakers. Nostalgic for a smaller, more manageable Europe, France, Italy and Belgium are keen that the euro zone or groups of like-minded countries should move ahead with deeper integration. By contrast, leaders of four ex-communist central European states, Poland, Hungary, the Czech Republic and Slovakia, warned on July 20: "One of the worst conclusions that Member States may draw from Brexit is dividing the EU in small clubs." There are some rays of light in this gloomy and confused picture, but they may be just a flash in the pan. A six-nation opinion poll showed public support for the EU surged to multi-year highs in the bloc's biggest countries in the days after the June 23 UK referendum. "When people realize the real implications of an exit, there's new-found support for the European project," said Francois Kraus of pollsters IFOP who conducted the survey. Perhaps, but that does not mean that European governments or their electorates are necessarily willing to sustain even the current level of integration, let alone a deeper monetary union. Rather, the poll may reflect a dawning awareness of a European paradise lost.