In August 2008, Russian forces crossed into Georgia, occupied South Ossetia and Abkhazia, and bombed targets beyond the two breakaway regions. The five-day war killed hundreds and displaced roughly 192,000 people, demonstrating to Finland and Sweden that Moscow would use military force against a neighbor outside NATO.
Georgia and the Prehistory of Hostility
For Finland and Sweden, neither a NATO member at the time, the invasion demonstrated that Moscow would use military force against a neighbor outside the alliance. Within months, both countries deepened defense cooperation with NATO. Their public opinion began a slow shift away from formal nonalignment.
By 2014, after Russia’s seizure of Crimea, Sweden and Finland signed host nation support agreements with NATO. Full membership applications followed only after the February 2022 invasion of Ukraine. Russia had already used armed force against Georgia’s separatist territories in the early 1990s and kept a military presence there.
In 2006 Moscow imposed a full embargo on Georgian wine, mineral water, and agricultural exports. A year later, a Russian missile struck a Georgian radar installation near Gori. By early 2008 Vladimir Putin had signaled that NATO membership for Georgia or Ukraine would force Russia to recognize Abkhazia and South Ossetia as independent states.
So the Bucharest summit in April 2008 did not trigger Russian hostility. It answered pressure that pre-dated any membership offer. Alliance heads of state declared that Georgia and Ukraine “will become members.” That wording committed NATO without a date or a path. That pledge followed, not preceded, Russia’s blockade, bombing, and threats.
Ukraine’s Reversal and the Crimean Catalyst
Before 2014, Ukraine’s parliament had written non-bloc status into law. That was 2010, and it barred membership in military alliances. Then Russian forces seized Crimea in February and March 2014, and Moscow backed armed separatists in Donetsk and Luhansk. That position collapsed.
In December 2014, the Verkhovna Rada voted 303 to 8 to repeal the non-aligned law, explicitly recommitting Ukraine to NATO integration. Public support for joining NATO stood at 28 percent in 2012. By 2015, it reached 47 percent.
The same pattern hit Finland and Sweden, which had stayed outside NATO for decades. After 2014, both countries began joint exercises with alliance members. In 2022, they applied for full membership.
Russia’s annexation of Crimea did not provoke NATO expansion; it convinced previously neutral states that Moscow’s border revisions made membership a survival issue.
Finland’s Fast Accession and the New Border
When Russia widened its war on February 24, 2022, Finland’s calculus shifted within months. Polls that had long shown support for NATO membership below 30 percent reversed to over 70 percent by spring. Helsinki and Stockholm applied together in May 2022.
Finland joined on April 4, 2023, adding 1,340 kilometers of direct NATO-Russia border, more than doubling the alliance’s previous 1,215-kilometer frontier. That new line runs from the Gulf of Finland to the Arctic, past Vyborg and St. Petersburg’s outer approaches.
Moscow had demanded in December 2021 that NATO stop expanding. Instead, its invasion produced the alliance’s fastest accession in modern history and its longest border with Russia.
Montenegro and the Coup Attempt
In October 2016, Montenegrin authorities arrested twenty people. Two were Russian military intelligence officers. They were plotting to assassinate Prime Minister Milo Đukanović and seize parliament on election night. The group planned to install a pro-Russian government and halt Podgorica’s NATO accession.
A Montenegrin court later convicted fourteen defendants, among them two GRU operatives tried in absentia. Despite the coup attempt, Montenegro deposited its instrument of accession on 5 June 2017 and became the alliance’s twenty-ninth member.
The plot demonstrated that Moscow treated NATO’s door as a threat to be preempted by violence, not as a provocation that expansion had created.