Earlier this month Russia vowed a bigger retaliation in response to NATO expelling what it called "undeclared intelligence officers" from Russia's diplomatic mission to NATO in Brussels. European and US officials have long viewed the diplomatic mission with suspicion, basically seeing it as a hub of Russian espionage in the heart of Europe.
On Monday Moscow announced it will suspend all activities of its mission to NATO beginning next month. Russian Foreign Minister Sergei Lavrov announced "In response to NATO’s actions, we are suspending the activity of the NATO military liaison mission in Moscow and will recall the accreditation of its staff from November 1 this year."
Additionally, "the operation of the NATO information office in Moscow that was set up at the embassy of the Kingdom of Belgium will be terminated," Lavrov said.
"If NATO has some urgent matters, it may contact our ambassador in Belgium on these issues," the foreign minister added of the dramatic tit-for-tat move which will serve to greatly lessen communications between the Western military alliance and the Kremlin.
Communications between Russia and NATO had already been limited and severely strained since Ukraine events of 2015 and Russia's acquiring Crimea, which the West has deemed a 'hostile annexation'. It also follows a couple years of European countries expelling alleged Russian intelligence officers as well as military members.
A NATO statement during the first week of October had accused Moscow of essentially using its diplomatic mission to NATO HQ in Belgium as a rotating spy shop.
"We can confirm that we have withdrawn the accreditation of eight members of the Russian Mission to NATO, who were undeclared Russian intelligence officers," the NATO statement said. "We can also confirm that we have reduced the number of positions which the Russian Federation can accredit to NATO [from 20] to 10."
The NATO official said further at the time: "NATO’s policy towards Russia remains consistent. We have strengthened our deterrence and defense in response to Russia’s aggressive actions, while at the same time we remain open for a meaningful dialogue."
2/2💬If anyone believed in the sincerity of those statements then today they don’t. Their real worth is clear to everyone. After the dramatic end of the Afghan era how can they get by without the bogeyman of “the Russian threat”. They can’t.— Russian Mission to NATO 🇷🇺 (@natomission_ru) October 7, 2021
The accusation had outraged Russian officials, with one senior lawmaker quoted widely in state media as vowing, "Russia will retaliate, and not necessarily in a symmetrical way." That retaliation appears to have come with Monday's mission closure, significantly heightening the diplomatic war with the West.