Russia's expulsion of four British Embassy staff was the minimum action it could have taken to preserve diplomatic dignity in the extradition dispute over Andrei Lugovoy.

Each of the measures announced today were presented as direct responses to Britain's decision on Monday to expel four Russian diplomats and to impose visa restrictions on government officials.

The Kremlin has adopted a tone of pained incomprehension at British actions, clearly seeking to cast Gordon Brown's new government as petulant and lacking in perspective. In limiting itself to four diplomatic departures, it is attempting to draw a line under the confrontation while casting London as entirely responsible for the crisis.

Russia also sought to deter the European Union from taking a united stance against Moscow over the failure to extradite Mr Lugovoy. Russia's permanent representative to the EU, Vladimir Chizhov, told Interfax that the statement of support for Britain issued by Portugal, which holds the rotating presidency of the EU, was "an unpleasant surprise".

"We would not like the principle of European solidarity to be applied selectively to Russia. That will inevitably harm Russia-EU relations," he said.

Moscow's intention is to isolate Britain and prevent the dispute harming Russia's wider interests, then wait until tempers cool so that relations with London can be gradually restored.

What Britain does next will determine the success of that strategy. David Miliband, the Foreign Secretary, has won EU support for his stance but needs concrete measures to raise the pressure on Moscow to cooperate.

Failure to agree a unified response will convince President Putin that he can simply sit out the crisis until Britain decides that it needs to repair relations.

Moscow has matched Britain's actions. Mr Miliband knows that he must decide now whether to raise the stakes in this game of diplomatic poker or acknowledge that he lacks a winning hand and quietly fold.

Explore UK News

• Crime News

• Education News

• Health News

• Scotland News

Times Recommends

• Phoebe Caldwell wins Times/Sternberg Award
• Raging against fake pop has its own pitfalls
• How a voice for everyone led to stalemate