Russia’s decision to end its mission to NATO seeks to undermine transatlantic unity and to deter the United States from pursuing additional escalatory measures. On Oct. 18, Russia announced it was ending its diplomatic mission to the Western defense alliance in Brussels and closing the NATO information office in Moscow after eight members of the Russian delegation were accused of being spies. While diplomatically significant, the move is unlikely to have a major impact on the extremely limited civil, political and military cooperation between Moscow and NATO following Russia’s annexation of Crimea in 2014. But it does risk straining relations within the bloc itself by driving wedges between the United States and its European partners on how to respond.

• In announcing the end of the NATO mission, Russian Foreign Minister Sergey Lavrov said that Moscow "will no longer pretend that any changes in relations are possible in the near future" and that the alliance “is neither interested in an equal dialogue nor in cooperation as equals.” Lavrov also indicated that Moscow would maintain future communication with NATO through bilateral channels and through the Russian ambassador to Belgium for urgent matters. 
• On Oct. 6, NATO expelled eight diplomats working at the Russian mission in Brussels, saying they were intelligence officers rather than military officials. The organization also reduced the size of the Russian representative office to only 10 staff members.
• In 2018, NATO reduced the size of the Russian delegation from 30 staff members to 20 in response to the poisoning of former Russian intelligence official Sergei Skripal and his daughter in the United Kingdom. 

Some European NATO members will probably call for a restoration of political dialogue with Russia, which the United States is unlikely to get on board with. Most critical incident avoidance communication is already conducted in a military-to-military manner between Russia and individual governments, though predominantly through the United States. The ending of Russia’s mission is thus unlikely to have an effect on such bilateral technical cooperation. The inability to engage with Moscow through NATO will, however, make European members increasingly reliant on Washington for such communications and, in turn, increasingly vulnerable to the United States’ mismanagement of relations with Russia. To avoid a potential U.S.-led escalation that is not in their interests, some European governments — especially those that have already floated reducing sanctions on Moscow (like France and Hungary) — are likely to eventually call to restore Russia’s presence at the defense alliance. But Russia would probably refuse to do so without NATO nations’ pledging serious political concessions, like abandoning plans to enhance their security cooperation with Ukraine, Georgia and Azerbaijan and other nations in Moscow’s perceived sphere of influence. This could, in turn, strain European members’ relations with the United States, as Washington will remain opposed to any significant removal of pressure on Moscow or reduction in support for Ukraine or Georgia for the foreseeable future. At the same time, Russia also may engage in bilateral security conversations with European states. But without the United States or NATO as the sole undisputed interlocutor between Europe and Russia, this could lead to policy contradictions as European states experiment with their own approaches to Moscow.

In addition to sowing discord among NATO members, Russia is also likely trying to deter the United States from imposing more sanctions and other penalties by sending the message that Moscow would respond disproportionately and undermine U.S. strategic priorities. Russia’s move to end its NATO mission likely comes as a surprise to the alliance’s member states, as a more symmetric response to the recent expulsion of Russian personnel may have involved Moscow decreasing the number of diplomats and officials from NATO countries in Moscow. But Russia likely felt that a more proportionate and non-escalatory response would have undermined the credibility of its deterrence to additional U.S. sanctions or a continuation of the diplomatic tit-for-tat with Washington, both of which the White House and U.S. lawmakers in Congress are currently considering. By showcasing its propensity for aggressive and unpredictable responses, Moscow is hoping the United States will opt against pursuing such punitive measures. A disruption of transatlantic unity was likely the best way to achieve this, as the Biden administration is currently attempting to rally European allies and NATO against China — an effort that could be undermined by increased internal tensions in the alliance. Russia could also make good on its recent threats to escalate the Donbas conflict on Ukraine’s eastern border, which would distract NATO from efforts to perform an effective “pivot to Asia” and expand its focus to counter a rising China, a major U.S. strategic priority.