The Lithuanian ambassador had been speaking for some time when the patience of Wilhelm Schönefelder, Germany’s long-serving ambassador to the European Union, finally ran out. What political advantage, Mr Schönefelder snapped, was Vilnius expecting to obtain by threatening to block this week’s negotiations on a new partnership agreement between the EU and Russia?

To participants, the curt exchange at an ambassadors’ meeting in Brussels last week was more than a simple disagreement over energy supplies. The spectacle of Germany taking the side of Russia against one of the new EU entrants – which Berlin had pledged to treat “equally” with other EU members – raised eyebrows across the room.