Russia has expelled four British diplomats in what the Kremlin called a "proportionate response" to the expulsion of four Russian diplomats from Britain earlier this week. Russia says it will stop cooperating with British counterterror efforts as well. Relations between London and Moscow have been strained since Russia denied an extradition request in the investigation of the '06 polonium poisoning case.
The US and EU have chided Russia for refusing to cooperate with the murder investigation, despite Russian claims that their constitution prohibits extraditions. Referring to today's expulsions, a Kremlin spokesman said "we were forced to take these measures," although he maintained that Russia wants "good and constructive cooperation…with all states, including Britain."