After seven years of work, Montenegro has finally been invited to join NATO:
NATO announced plans on Wednesday to enlarge its membership, a move that brought an angry response from Moscow....In Moscow, a Kremlin spokesman, Dmitry S. Peskov, said that NATO’s expansion would be met with retaliatory measures from Russia, Reuters reported, and Russia was also reportedly planning to halt joint projects with Montenegro.
In case you're geographically challenged, the map on the right shows NATO's current members (in dark blue) as well as the location of Montenegro. As you can see, Montenegro is across the Adriatic from Italy, about 500 miles from Ukraine and a thousand miles from Russia. Joining NATO is not exactly a threat either to Russia's borders or to its sphere of influence.
But it used to be part of Yugoslavia, which was a Soviet ally back in the day. So this requires Vladimir Putin to stamp his feet and claim that Russia's heritage is being attacked by the West, blah blah blah. You may safely ignore it. This hardly came as a surprise to the Russians, and it hardly represents a threat to them. It's just an opportunity for a bit of jingoism to shore up the home market.