A British exit from the European Union is no longer unthinkable. Britain’s marginalization is, actually, quite likely. And it seems that France and Germany are not overly concerned about a British departure. EU-federalists in Brussels and elsewhere appear even to rejoice at the prospect of getting rid of the UK—a country that, since joining in 1973, never felt entirely comfortable with being sucked into continental politics. Britain is widely seen as arrogant, selfish, and too close to Washington. It is perceived as being the main obstacle on the historic path towards a closer union.

But those who shrug at the prospect of losing Britain at the heart of Europe should think twice. Britain is a key element for the complex balance of power inside the EU. It is also still a power with global reach. Without Britain’s active participation, the EU can forget its dreams of becoming a global power.

The three big players in the EU—France, Britain, and Germany—have always held very different views on what the union is good for. Britain wants a single market and as little interference as possible in its domestic politics, although where possible it is glad to use the EU to amplify its foreign policy clout.

France wants the EU in order to stay relevant on the global stage, and it wants to use the EU as a protecting shield against globalization. It also sees European integration as a means of preventing German hegemony, as a sort of life insurance against a neighbor by which it was shockingly defeated twice—in 1871 and 1940. To reach these national goals it is ready to go a long way to accommodate Germany.

The German vision of the EU has, by contrast, always been federalist. European unification was a key vehicle for West Germany to become respectable again. Embedding a united Germany in a more deeply integrated European Union has been seen by the europhile elites in Germany as a lasting guarantee against the re-emergence of the darkest chapter in the country’s history—racist nationalism and war. Today all important parties still read from the federalist sheet and “more Europe” is accepted as the solution to any European problem. In practice, however, Germans are as keen as others to keep control of their fate. “Political union” in today’s Germany does not mean a United States of Europe, but an arrangement where Berlin can have greater control over countries in crisis.

In normal times, these different views and interests could be reconciled. EU leaders met, sorted out their differences, and in the end everyone could claim a victory to his or her domestic audience. But with the stress of the eurocrisis, this appearance of unity has been broken. A major divide has appeared between the eurozone and the rest. The 17 member states that share a common currency have separate interests, agendas, and meetings, and in the future they may even have separate institutions.

For a country such as Poland that aspires to membership in the eurozone, this split is a temporary problem. But for Britain, which has clearly positioned itself outside the euro area, this means much more. It means that the days of its participation in the EU’s leadership trio may be over. Britain is no longer sitting at the top table; France and Germany are calling the shots. And the more the eurozone appears to move towards closer union, the more the eurozone develops its own centrality and dynamic, the more the value of British EU membership diminishes. The danger now is that this dynamic will move Britain outside the EU, or at least to its margins.

That would be a major blow to the EU. It would shatter the very foundations of European politics. What made the EU so strong and attractive for decades was the fact that it integrated Europe’s main powers. It was the specific mix of policies this blend has generated: a balance between French statism and British liberalism, with Germany somewhere in the middle. Without Britain, the liberal element will be considerably weakened. And that will have an impact far beyond Britain, as many EU members in the north, and some in the east, are quite attached to the UK and its political and economic culture. The risk that British detachment will strengthen centrifugal forces in the EU is real.

Also the idea that without British interference, Germany and France will find it easier to move the union forward may prove to be a major misconception. With Britain taking a more detached role now, it has already become much more visible that Germany and France disagree on nearly everything. Behind much of that disagreement lie fundamental differences of views on sovereignty, nation and statehood, but also on economics. While Germany is built on what could be described as a hard core of economic nationalism, French nationalism is political in its very nature, built on notions of citizenship and the republic that date back to the French revolution.

Moving Britain out of the EU’s center might therefore not lead to more cohesion. To the contrary, it might accentuate divisions and strengthen centrifugal forces. Instead of removing an obstacle to closer union, it could signal the beginning of the end of an EU that has been built on the idea of an integration of diversity.

But maybe the biggest blow of a “Brexit” would be to the bloc’s ambition to become a major player on the world stage; its ambition of becoming a force capable and willing to defend its views and interests and serving as a second pillar of the liberal world order, alongside the United States. Losing Britain’s power resources—a strong military, a veto on the UN Security Council, abundant experience in international politics, and diplomatic know-how—would end Europe’s global ambitions and turn it, at best, into a regional player with some interests in the eastern and southern neighborhoods. An inward-looking EU could live with Britain’s departure, but for an outward-looking EU this would be a deadly blow.

Keeping Britain at the center of the EU is therefore vital. But it has a price. It would mean limiting integration and not challenging the essentials of sovereignty. European Council President Herman Van Rompuy said recently: "What we're getting at now is the crux, the hard core of sovereignty and solidarity. There are number of taboos that have to be touched." It is exactly this development which frightens British voters and is pushing the UK away from the EU.

However, theprospect of limiting integration should not be too frightening. The euro crisis has demonstrated that even Germans, the historic drivers of European integration and the champions of federalism, are much less willing to give up sovereignty than they pretend. For Germans too, integration has reached its limits. They still talk the federalist talk, but they are as hesitant to walk the walk as anybody else. And with the European Central Bank taking over the main responsibilities for crisis management, German willingness to move towards something like the United States of Europe has slackened considerably.

Berlin, as the central power in Europe, now urgently needs to build bridges with London. One way to do so would be to make a liberal growth agenda a top priority, something that might please British voters. Another way would be to start to take the project of a common foreign and security policy seriously, injecting new energy into the European External Action Service, and making foreign policy a priority at EU summits; this would appeal to Britain’s aspirations to continue to play a global role.

Instead of talking the federalist talk, which is pushing Britain away from the heart of Europe, continental leaders must make London an offer that it cannot refuse. Otherwise they may find out one day that by saving the euro, they destroyed the European Union.