If Russia follows through on its foreign minister (and eloquent troll) Sergey Lavrov’s threat, and expels British diplomats from Moscow, then Britain, France, Germany, and the U.S. should expel Russia’s ambassadors to their capitals. Although that might seem like an excessive escalation, there are two reasons why it would be appropriate.
First, the Skripal hit was an unprecedented outrage on British soil. As well as putting two civilians under British care in critical condition, the attack left a police officer seriously ill and endangered the population of Salisbury. Even setting aside how outrageous this attempted assassination is in itself, Russian President Vladimir Putin could have at least chosen a limited attack methodology to kill Skripal without endangering so many others.
Second, thus far, Prime Minister Theresa May’s response to this atrocity has been carefully calibrated. May has sent a message of great displeasure and unified British allies around her government. That said, it’s also notable what May hasn’t done. She hasn’t ordered the Russians to vacate their intelligence compounds in north London. She hasn’t, as far as we know, authorized covert action against Russian actors inside Russia. And she hasn’t yet ordered the Russian ambassador to depart.
That would be the logical next step if Russia now escalates.
After all, it’s clear that the Russian government underestimated the speed and success of Britain’s effort to unify its allies in its common support. Considering difficult Brexit negotiations with Germany and President Trump’s previously stated affinity for Putin, the Russian president likely assumed that May’s government would get words of support and little else.
In contrast, Putin has been met with a joint statement of aggressive condemnation from Britain, France, Germany and the U.S., and now faces the real possibility of sanctions action at upcoming E.U. and NATO summits. President Trump, to his credit, has also been explicit in blaming Putin.
Britain and its partners must not allow Putin to regain the strategic initiative here. But if Russia expels British diplomats and there’s no reply, that’s exactly what will happen. Once again, Putin will come across as the leader who is willing to escalate his way to victory and avoid serious consequences for his attacks on allied interests.
In contrast, were Putin to escalate, expelling the Russian ambassadors from London, Berlin, Paris, and Washington would send a clear signal that he has miscalculated: that he has in fact crossed a red line.
What if Russia escalates again?
Simple: The allies should push FIFA to relocate the World Cup out of Russia, perhaps to Poland and Ukraine, as some MPs are already discussing. That, I suspect, is an action Putin is desperate to avoid.

