Finland's NATO Membership Riles Russia.

Finland formally joined NATO on Tuesday, ending its era of military non-alignment and drawing a threat from Russia of "counter-measures". The move roughly doubles the length of the border that NATO shares with Russia and bolsters its eastern flank as the war in Ukraine grinds on with no resolution in sight. Finnish President Saul Niinisto said Finland's most significant contribution to NATO's common deterrence and defence would be to defend its own territory. The Kremlin said Russia would be forced to take "counter-measures" to Finland's accession.