Perhaps the greatest academic growth area over the past twenty years or so has been “European integration studies”, a field that has both analysed and boosted support for the European “project”. Almost all of its practitioners have proceeded from the assumption that the process of integration is – must be – “irreversible”. It is the intellectual equivalent of the principle of the European acquis communautaire by which powers, once surrendered or pooled, cannot be retrieved. Or, more unkindly, one might see it as a “European Brezhnev doctrine”, by which socialism, being inevitable, could not be allowed to fail in any country in which it was already established.

But what if this is not so? What if, as the Croatian political scientist Josip Glaurdic, an expert on the collapse of Yugoslavia, once quipped, what we really need is a school of “European disintegration studies”?

The stark truth is that in the past century or so of European history there have been many more examples of disintegration than integration.

Take the cases of Austria-Hungary, Yugoslavia and the Soviet Union. Each was an attempt to create a supranational entity that its proponents (and inhabitants) imagined lasting, if not for ever, then nearly so. But in the end, each of them collapsed. And if these examples provide any guide, the days of the European Union are numbered, unless it can effect fundamental reform.

What caused their collapse? Each case is different, of course, but the common denominator was an intractable crisis that lasted for roughly a decade and for which there was ultimately no solution, except the end of the state and a new beginning.

Austria-Hungary could not contain the burgeoning desire for self-determination among its myriad peoples within a centralised monarchical framework. Efforts initially focused on a revised federal solution giving more power to the various nationalities. But the more power the centre conceded, the more power its peoples demanded. Eventually, the empire endured a flight into war in 1914 as the leadership tried to stamp out the south Slav problem once and for all. Amid the carnage, the Czechs in particular pressed for complete independence, and others did the same. At war’s end, the Allied powers granted them their wish.

In Yugoslavia and the USSR the problem was socialism, which had exhausted itself by the 1980s while continuing to demand excessive burden-sharing among their respective national groups, some of which had a history of conflict.

In the case of the EU, the problem is the ideology of “Europeanism” among the continent’s ruling elites, who transferred power from national capitals to the central European institutions at a faster rate than most electorates were willing to accept. This was tolerated in the good times: most voters did not pay a great deal of attention to what powers their rulers were giving up, as long as life continued to improve.

However, things changed when the EU finally hit a major crisis and the institutions found themselves responsible for matters, such as monetary and migration policy, for which there was no European consensus. Not only has this rendered decision-making very tricky, but the EU has found that it lacks the legitimacy to impose decisions for the sake of the common European good.

Decision-making has become a two-stage process. At first, there is paralysis because the institutions cannot find a solution with which everyone can agree. Then, when crisis turns to emergency, power politics takes over and the stronger states impose self-interested decisions on weaker ones.

This is unsustainable. After many good decades, the EU is failing in its promise to deliver lasting prosperity and stability. Now it is reneging on its commitment to democracy. Unless the EU can find solutions to the problems Europe is facing that are acceptable to its members – and so far we have waited five years for it to end the eurozone crisis – the Union will be on a glide path to collapse.

Can the EU turn its fortunes around?

Perhaps, but recent history does not hold out much hope. Potentially, individual states could be allowed to opt out of the parts of the acquis to which they object, recasting the Union on the basis of “variable geometry”. Yugoslavia and the Soviet Union both confronted the same issue and to some extent the constituent republics were allowed to go their own way.

But this autonomy operated within strict limits. The elites were still boxed in by their basic commitment to socialism and burden-sharing, which limited the scope of discussions on how to revive the economy and redistribute power within the Union. Eventually, as living standards tumbled, the richer republics – Slovenia and Croatia in Yugoslavia, and the Baltic states in the Soviet Union – become ever more resistant to sharing their scarce resources. As the economic and political crisis deepened and the ship of state started sinking, they each jumped off for safety.

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Similar problems prevail in the EU. Many of the elites are trapped by their belief that Europe cannot repatriate powers to national capitals for fear of opening the proverbial Pandora’s box, containing all the evils in the world. Britain will demand greater control over immigration and welfare, France a curb on the free market and Poland control over environmental policy. By the time member states have each reclaimed the areas of policy they most cherish, there will be no union left and Europe will descend into nationalism and – just possibly – armed conflict.

The alternative is that the eurozone makes a concerted drive towards becoming a single state in order to save the common currency and provide for the common defence. But recent history offers no precedents for a move towards deeper union at the moment when crisis strikes. Instead, separate national interests sharpen. Most eurozone members probably recognise the need for a political union, but they will accept it only if the Union is designed in a way that suits their various specific requirements. One wishes it were otherwise, but experience shows we shouldn’t hold our breath as we wait.

If the EU is facing a crisis for which there is no apparent solution, then what does recent history tell us about the manner of its potential collapse?

One point is that this can happen even if most people do not want it. In Austria-Hungary, Yugoslavia and even the Soviet Union, most people were afraid of life on the outside and initially pursued their national goals within the familiar confines of the federal entity. Another is that, when the final collapse does come, it can happen so quickly that almost everyone is caught unawares. Even in 1989, few people foresaw the collapse of Yugoslavia or the Soviet Union, which is one reason why malcontent members pushed their demands so hard.

From start to finish, the process of collapse exposed other common features.

One is an increasing resort to “self-help” solutions. In all these cases, as the crisis deepened and the central institutions became paralysed, power informally shifted from the union to the national level as individual members sought their own, unilateral solutions. In both the USSR and Yugoslavia, the federal republics began to assert control over economic policy, in violation of union law, and refused to “export” essential goods (such as food) or surrender tax revenues that were needed at home.

A second feature is that, as the overarching structure buckled, so the individual parts began to fracture. At the end of the Soviet Union, Azerbaijan broke when the Armenian enclave of Nagorno-Karabakh rejected the authority of Baku. Similarly, Abkhazia, South Ossetia and Adjara broke away from Georgia, Transnistria from Moldova and Chechnya from Russia (although this was recaptured, in Vladimir Putin’s first notable act as president). Meanwhile, as Moscow withdrew from its eastern European hinterland, the bi-ethnic state of Czechoslovakia also collapsed.

In Yugoslavia, the disintegration of the federal structure was mirrored by the dis­integration of the individual republics. When Croatia and Bosnia broke away from the union, so the large Serbian minorities within those republics broke with the emerging independent states in an attempt to remain part of Yugoslavia. In parallel, Kosovo made its first, unsuccessful bid for independence from Serbia.

A third common feature is the increasingly forceful exercise of power by the core state, which had the greatest stake in the survival of the union and primary responsibility for holding it together. Austria launched a military crackdown against secessionism in the Balkans. In the Soviet Union, Moscow deployed the Soviet army to the Baltic states and the Caucasus. And in Yugoslavia, the Serbian leader Slobodan Milosevic launched the “anti-bureaucratic revolution” in Montenegro, Kosovo and Vojvodina, and ultimately sent the Yugoslav army in to Slovenia, Croatia and Bosnia.

Paradoxically, attempts to resist the fragmentation of the union were followed by active attempts to loosen it. This happened at the point when the core state realised it could not hold the union together in its old form and sought to salvage what it could in the new circumstances.

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In some cases, this was a gradual process. As early as 1867, the Habsburg empire was transformed into the dual monarchy, giving Hungary almost complete autonomy within a system hitherto dominated by Austria. Yugoslavia also loosened in 1974. The evidence suggests that such moves can buy time for the union, something that may give the UK breathing space in the coming years. The Austro-Hungarian empire survived five decades after its reforms and the devolution of power to the individual republics sustained Yugoslavia for another 16 years.

But moves to loosen the union at a more advanced stage of decay can have the opposite effect. Attempts by Belgrade and Moscow in 1989-90 to reconstitute their unions as loose confederations against a backdrop of crisis and threats of secession proved futile. Such moves were interpreted as a sign of weakness, which only served to galvanise the secessionist forces.

A final feature of all three cases is the pivotal moment when the second major power leaves the union. History suggests that unions can survive the loss of a small member state, such as Ireland from the UK in 1921. Conceivably the Baltic republics could have left the USSR, Slovenia could have bailed out of Yugoslavia, and in the EU context Greece could quit without the whole Union collapsing. When the second state quits, however – Ukraine, in the case of the USSR, and Croatia in Yugoslavia – the loss critically destabilises the balance of power within the union.

At this point, the smaller states are left in a dangerously asymmetrical relationship with the dominant state and must leave to avoid becoming de facto colonies of a single, unrivalled power. With Croatia’s departure, Yugoslavia in effect morphed into Greater Serbia and states such as Bosnia and Macedonia were forced to claim an independence they had not previously sought. Once Ukraine left the Soviet Union, no state would have been able to keep the power of Russia in check.

Yet there is one interesting variation of this pattern, namely “central secession” – that is, when the core state itself quits the union. In the Soviet Union, the final scene in the drama of its collapse was Russia’s declaration of independence in 1990, which Boris Yeltsin led in order to marginalise Mikhail Gorbachev, whose power derived from the Soviet federal institutions. At this point, the Soviet Union in effect ceased to exist and the central Asians and Belarus, the last states standing, became independent by default. In Yugoslavia Milosevic and Serb nationalists first tried to reconstruct the whole federation as a Serb-dominated “Serboslavia”, settling for a “Greater Serbia” when this foundered on the opposition of Slovenia and Croatia, which were practically extruded from the federation. In the Austro-Hungarian context, it was the peri­pheral nationalisms – using the stresses of war – that did for the Habsburgs in the end, but at other times in its history the empire was also under very great pressure from German and Hungarian nationalism.

In other words, during the process of collapse, the core power can pass through stages, in which it first tries to hold the union together by force, then pursues compromise with its secessionist partners, and finally bails out of the union, bringing about the final collapse that it initially tried so hard to avoid.

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If this is how unions collapse, what can we infer from it about the future of the EU? One thing we should see is states resorting to unilateral solutions to urgent problems, as the EU institutions prove increasingly ineffective. In fact, this is already happening. Some eastern European states have been quietly opting out of parts of the single market for some years now, insisting instead that companies operating in strategic sectors harmonise their activities with the national government’s political objectives. Anyone who doubts this should try to buy farmland or open a utility company in Hungary. They will be in for a nasty surprise.

In recent weeks, states in central and eastern Europe, including Germany, have also abandoned their treaty obligations on borders and asylum (Schengen) as the burgeoning migrant crisis has rapidly changed their political circumstances.

We will also see member states starting to fragment and, indeed, it is no coincidence that Scotland made a bid for independence at a time of deepening crisis in the EU. Scots (just about) feel their interests are secure in a United Kingdom which is locked in to a larger, supranational structure that exercises control over London. But if Britain were to abandon the EU and fully restore its own independence, Scotland would be both isolated from Europe and subordinate to a dominant English state. If and when the Scots vote to leave, the position of Wales and Northern Ireland in an even more asymmetric union could be untenable.

In Spain, Catalonia is sensing Madrid’s weakness, given its dependence for liquidity on an organisation in a state of existential crisis. Its grievance, that Catalonia pays in far more than its gets out, is nothing new but the opportunity for escape is unprecedented. Belgium is also at risk of breaking apart; so is Italy, with the north seceding and then breaking up into smaller parts such as South Tyrol.

So, too, are the western Balkans, which lie within the Union’s hinterland. Over the past decade, as the United States wound down its security commitment, the EU has played the dominant external role in the region, enforcing the sanctity of borders in the face of resistance from unhappy minority groups such as the Bosnian Serbs and Macedonian Albanians, who would ideally take their territory and go somewhere else. By and large, peace has prevailed until now. But as the EU’s leverage wanes, so fragile states are fracturing. After a grave political crisis this year in Macedonia, the country’s future is hanging in the balance. And with little to fear from a crisis-stricken EU, the Bosnian Serbs have announced plans for a referendum on independence in 2018, a move that would inevitably lead to unification with Serbia.

As the EU comes under ever greater stress, we will see Germany, as the dominant state, asserting its power more forcefully over the rest of the Union in an attempt to hold it together. This almost certainly does not imply a resort to violence – Germany is a very different country in very different circumstances from Russia and Serbia in 1990.

But already, Berlin has trampled on the interests of the southern periphery by demanding a punishing programme of austerity as the price for providing the credit line that holds the eurozone (and, by extension, the European project) together. And this summer, despite vehement protests from the eastern Europeans, Germany has insisted that all EU member states take a quota of the migrants pouring in to Europe and whose presence threatens one of the pillars on which the Union is built – the freedom of movement.

If events follow the established course, this exercise of raw power will be accompanied, after a while, by concessions on loosening union. Already Britain has initiated discussions and other states, such as the Netherlands, Denmark and Poland, may soon line up behind it. The next step is for Germany to calculate that compromise is the way to avoid the early collapse of the Union. Whether these efforts succeed depends on whether the EU is facing its 1867/1974 or 1918/1990 moment.

Assuming it is the latter, then the pivotal moment will come when the second state finally throws in the towel, destabilising the balance of power within the EU. In this respect, the EU is a more complicated entity than Austria-Hungary, the Soviet Union and Yugoslavia because it has not one, but two second-tier states, Britain and France. But if one of them left, and Britain is closer to the exit, those states that remain would face the unpalatable prospect of remaining in a German empire writ large, or leaving.

The first to go would probably be Eurosceptic states such as Denmark, Hungary and the Czech Republic. But, with each departure the rump union will become ever more German-centred, with the result that others will be likely to bail out rapidly.

Precedent suggests that Germany, too, could secede. If the EU were to follow the Soviet model, Jean-Claude Juncker or Donald Tusk would play the role of Mikhail Gorbachev, trying to hold the Union together, while a Yeltsin-like figure would emerge within Germany, making a bid for independence in order to sideline the EU. More likely, however, the EU would follow the Yugoslav model and, like Serbia, Germany would be the last man standing after everyone else has left or has been forced out for one reason or another. The one exception to this could be Austria, which clings to Germany as Belarus once did to Russia and Montenegro to Serbia.

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As of 2015, the EU is not at the point of no return as Austria-Hungary was by 1918 and the Soviet Union and Yugoslavia were by 1990. There is still a chance of turning things around. Another flare-up in the euro crisis could lead to either the full political union it requires to function or an orderly dismantling of the common currency. But this is where historical forces give ground to more contingent factors. And the wild card here is elections.

In both the USSR and Yugoslavia, a round of relatively free elections in 1990 (the first in their history) gave rise to nationalist parties across the two unions, with explicitly rejectionist agendas. In Yugoslavia, the Croatian Democratic Union led by Franjo Tudjman successively severed all remaining ties with Belgrade and eventually organised a referendum on independence. In Slovenia, DEMOS – the Democratic Opposition of Slovenia – took the same path.

Meanwhile, in the USSR, elections to the regional soviets brought to power overtly nationalist governments in the Baltic states, the Caucasus and Moldova whose primary goal was to deliver independence.

We are still awaiting the moment when radical Eurosceptic parties take power in Europe with an explicitly rejectionist agenda. Britain’s Conservatives hardly fit this description, because they are politically mainstream, and the UK is a special case whose status could be renegotiated. Elsewhere, however, radical parties such as the Front National in France, the Party for Freedom in the Netherlands and the Sweden Democrats are (or have been) leading in opinion polls across the continent. It is perhaps only a matter of time before one of them gets into government.

So here is what could happen, in what is an apocalyptic but perfectly plausible sequence of events.

In 2016 or early 2017, Geert Wilders’s Party for Freedom wins the Dutch parliamentary elections and leads an overtly rejectionist coalition. Sensing the threat, Germany unilaterally “grants” Britain a new deal on membership, including curbs on benefits for EU immigrants, which, in the final analysis, do not matter that much to Berlin. There is no broader discussion about this around the EU, and France, which opposes concessions for Britain, is marginalised. Britain votes to stay in (just, thanks to the Celtic vote) on the basis of the new deal. But matters do not end there.

In an increasingly radicalised atmosphere, caused mainly by the refugee crisis, Marine Le Pen wins the French presidential election in April 2017 and demands a comparable package of concessions, this time on things that really do matter to Germany, such as French membership of the eurozone, plus much tougher restrictions on immigration – all on pain of secession.

Fearing a domino effect around the EU, Germany refuses. This triggers France’s exit, which critically destabilises the rest of the EU. The Netherlands is the next to go. Within weeks, most other states announce their departure, including Britain, which never got to implement its new deal, and by 2018 the EU is all but dead. For the UK the only silver lining is that Scotland remains in, partly because the option of “independence” within the EU has disappeared, and partly in order to seek shelter amid the fallout from the collapse of the European project. With the passing of the EU, the UK remains the only modern example in history of a successful, multinational parliamentary union.

This is an extreme scenario in some ways, but very optimistic in others, not least because it does not presume war. Nor does it presume that any of the other crises facing the Union will turn into an emergency for Europe, be it Russian adventurism on the EU’s eastern flank, conflict in the Middle East, international or domestic terrorist attacks or a sudden collapse of the common currency, all or some of which are more likely than not to happen, and all of which require a functioning EU in order to master.

The collapse of the EU would, however, be hard to contain and the shock would be felt around the world. The next few years may be the time when everything goes wrong – not just in Europe but everywhere, ultimately, because of it.

If so, we will have cause to remember the words of Count Ottokar Czernin, Austria-Hungary’s foreign minister for most of the First World War: “We were bound to die. We were at liberty to choose the manner of our death and we chose the most terrible.”

Brendan Simms is the director of the Forum on Geopolitics at the University of Cambridge

Timothy Less is the director of the political risk consultancy Nova Europa and a former British diplomat