By any measure, it has been a year from hell for the European Union. And if Britons vote to leave the bloc, next year could be worse.
Read more: Europe's year from hell may presage worse to come - Yahoo News
Not since 1989, the year the Berlin Wall fell and communism crumbled across eastern Europe, has the continent's geopolitical kaleidoscope been shaken up so vigorously.
But unlike that year of joyous turmoil, which paved the way for a leap forward in European integration, the crises of 2015 have threatened to tear the Union apart and left it battered, bruised, despondent and littered with new barriers.
The collapse of the Iron Curtain led within two years to the agreement to create a single European currency and, over the following 15 years, to the eastward enlargement of the EU and NATO up to the borders of Russia, Ukraine and Belarus.
That appeared to confirm founding father Jean Monnet's prediction that a united Europe would be built out of crises.
In contrast, this year's political and economic shocks over an influx of migrants, Greek debt, Islamist violence and Russian military action have led to the return of border controls in many places, the rise of populist anti-EU political forces and recrimination among EU governments.
Jean-Claude Juncker, who describes his EU executive as the "last chance Commission", warned that the EU's open-border Schengen area of passport-free travel was in danger and the euro itself would be unlikely to survive if internal borders were shut.
Juncker resorted to gallows humor after the last of 12 EU summits this year, most devoted to last-gasp crisis management: "The crises that are with us will remain and others will come."
His gloomy tone was a reality check on the "we can do it" spirit that German Chancellor Angela Merkel - Europe's pre-eminent leader - has sought to apply to the absorption of hundreds of thousands of mostly Syrian refugees.
Merkel has received little support from her EU partners in sharing the migrant burden. Most have insisted the priority is sealing Europe's external borders rather than welcoming more than a token number of refugees in their own countries.
This is partly due to latent resentment of German dominance of the EU and payback for its reluctance to share more financial risks in the euro zone.
Some partners also accuse Berlin of hypocrisy over its energy ties with Russia, while friends such as France, the Netherlands and Denmark are simply petrified by the rise of right-wing anti-immigration populists at home.
One of the sharpest rebuffs to sharing more of the refugee burden came from close ally Paris. Prime Minister Manuel Valls said of Merkel's open door policy toward Syrian refugees: "It was not France that said 'Come!'."