There's no knowing how and where it will all end. But it is clear with every week that passes in Europe's biggest crisis that Britain and the rest of the EU are heading in starkly different directions.

Minds concentrated by almost three years of euro crisis, Berlin for months has been demanding to reopen the EU treaties to facilitate a big pooling or surrender of – depending on your point of view – national sovereignty to facilitate a federalised eurozone, with what amounts to a core European government of an expanding 17 countries that would take on prerogatives over tax-and-spend powers. Britain is well out of that.

Last week the European commission signed up to the German blueprint, while unveiling problematic EU legislation making the European Central Bank the policeman of the eurozone banking sector. Britain will have no part of that, either.

On Tuesday the German foreign ministry extended the federalising economic policy-making to foreign and defence, along with 10 other EU foreign ministries carefully chosen to reflect the non-UK EU mainstream – small countries, big countries, single currency members and those outside the euro, core western states and newer east European countries. The likelihood is that the 11-country consensus will swell into a majority among the EU's 27. Britain also stands apart from this. The 11 include Germany and France, the big ones, plus Italy, Spain and Poland – after Britain the biggest EU countries.

In short, Britain's isolation becomes more fixed, while the cross-Channel gap widens to become less than bridgeable. More in sorrow than in anger.

There is ample support and sympathy for Britain's role in Europe, for the quality of its contribution in foreign, security and defence policy, for its pragmatic liberalism, its role in upholding the freedoms of the single market, its anti-protectionist instincts, the relative quality of its shrinking army of eurocrats.

But there is also exasperation with the negativity, the lack of team spirit, the seeming resolve to exploit Europe's biggest ever predicament for national or even party political ends.

It becomes ever harder for London to construct more than ad hoc, single, issue-driven alliances in Europe. Poland, for example, was a driving force behind Tuesday's radical foreign and security policy proposals. Until a couple of years ago it was a natural British ally in the European contest. It owed France nothing since Paris rightly saw the expansion of the EU to eastern Europe as a zero sum game diluting French clout. And history dictated that Warsaw would be wary of Berlin. But it has since given up on Britain, calculating that the national interest means making common purpose with Germany.

On the euro, on a future open eurozone political federation, on the transfer of still national powers to European institutions, there remain ample differences between the main EU states, most fundamentally between Germany and France. Some things never change.

But that is not a drifting apart, rather an argument over fixing the terms of getting closer together. It is a political process where Britain is increasingly outside looking in.

All the evidence, argument, and logic point to the European treaties being re-opened for further refinement within a year in order to make possible the transfer of further sovereign national powers to Brussels. The stakes are too high to accommodate David Cameron's problems.

Either he manages to renegotiate the terms of UK membership - he's not owed a lot of favours - or he has to order a British referendum. Seen from Brussels, the question is less whether there will be a referendum, rather what's the question on the ballot paper.