What’s the diplomatic message behind Kremlin’s largesse?

There appeared to be two separate messages coming out of the Kremlin on Friday, when Foreign Minister Sergei Lavrov announced that 31 American diplomats would be expelled as retaliation — and then Russian President Vladimir Putin announced no U.S. diplomats would be ousted. Lavrov’s announcement of a tit-for-tat expulsion — President Obama said on Thursday that 35 Russian diplomats would be expelled from the U.S. — is a common practice that goes back to the Cold War.