At the end of September, Cameron announced, almost as an aside, that his government intends to withdraw from a Europe-wide system of cooperation among judicial and police authorities. The decision affects more than 130 regulations, which also include the European arrest warrant. If Great Britain's intentions are serious, it will become much more difficult for German authorities to apprehend criminals who have fled to Britain.
If Cameron also wants to bring other powers from Brussels back to London, it will openly contravene the preamble of the EU Treaty, which the British ratified. In the preamble, all member states pledge "to continue the process of creating an ever closer union among the peoples of Europe."
The Europeans are unwilling to grant the British further special rights, and the next conflict is already taking shape. Last week, 11 euro-zone countries resolved to introduce a financial transaction tax. The French and the Germans, in particular, were tired of waiting for the British. Officials in Brussels now fear that London will attempt to block the tax.
But it isn't the case that the government in London is keeping itself out of the affairs of the euro zone. When Chancellor of the Exchequer George Osborne vociferously called for the introduction of euro bonds, for example, he inflamed the dispute between the north and the south.
EU High Representative for Foreign Affairs Catherine Ashton must also contend with her fellow Britons' repeated interventions whenever she or other EU representatives seek to issue statements on behalf of the EU at the United Nations or elsewhere. The government in London has even deployed a team of legal experts to find arguments to block joint EU statements.
For instance, the British insist that discussions in the World Health Organization (WHO) in Geneva have nothing to do with foreign policy. Instead, London argues, such discussions relate to healthcare policy, over which Brussels has no control. The EU and its predecessors "have over six decades contributed to peace and reconciliation," the Nobel Committee wrote. But at the moment its member states are engaged in an ugly feud.
People in Brussels and in many member states are so upset about Britain's behavior that a scenario is becoming conceivable that all sides had hoped to avoid until now: If the many opponents of Europe among the Tories prevail, the European treaties will have to be renegotiated.
Euro Group President Jean-Claude Juncker and European Commission President Barroso had already planned to do so, but on completely different terms. They wanted to convene a constitutional convention, which they hoped would ultimately lead to something like a United States of Europe. The visionaries wanted to create the position of euro finance minister, and they also imagined a shared foreign and security policy, even to the point of combining all of the member states' military forces.
Now it could happen that a convention initiated by Great Britain will achieve precisely the opposite result, namely the division of Europe. This, at least, is the fear that has senior crisis managers in Brussels worried at the moment. Greece's financial problems are no longer at the top of their list, but rather the possible departure of one of Europe's largest countries.
No one in Germany wants this, but no one with any political responsibility has any illusions about London's European policy, either. "We find it regrettable that England is taking certain steps without us," says Rainer Brüderle, the parliamentary leader of the business-friendly Free Democratic Party (FDP). But he also knows where Germany's policy priorities lie. "We must eliminate the birth defect of the euro, and we need a stronger political union." And that, apparently, will only be achievable without Great Britain.