BRUSSELS – Germany, Poland and Sweden announced a coordinated, tit-for-tat expulsion of three Russian diplomats Monday, in retaliation for Moscow's decision last week to expel diplomats from the three countries for monitoring the protests that followed the jailing of opposition leader Alexei Navalny.

Russia accused the diplomats of participating in the protests, which the three nations, all members of the European Union, denied. But Moscow's actions were judged by experts to be more serious, since they represented a calculated insult to the E.U. and its foreign-policy chief, who was engaged in a news conference with his Russian counterpart, Sergey Lavrov, when the expulsions were revealed.

The visit of the European official, Josep Borrell Fontelles, was controversial from the start, because it took place two days after Navalny was sentenced. Borrell defended the trip as an important effort to establish better relations with Russia and as a chance to state in person European demands that Navalny be freed.

But some member states, like Poland and the Baltic nations, thought the timing was inappropriate. Borrell was also criticized for not visiting Navalny and for the way he stood by as Lavrov called the E.U. an "unreliable partner" and accused European leaders of lying about Russia's responsibility for Navalny's poisoning with a military-grade nerve agent.

Borrell responded that "the Navalny case is a low point."

The expulsion of the three European diplomats, whom Russia accused of participating in "illegal demonstrations," hardly improved matters.

After Russia refused to reverse the expulsions, on Monday, all three nations responded by each expelling a Russian diplomat.