NATO invites Montenegro to join, prompting Russian threat of retaliation

On Wednesday, NATO formally invited Montenegro to join the military alliance. Montenegro — a small coastal Balkan country of 650,000 people sandwiched between Albania, Serbia, and Bosnia and Herzegovenia — would be the first new NATO member since 2009, when Albania and Croatia joined the alliance. Russia opposes any eastern expansion of NATO, and Kremlin spokesman Dmitry Peskov warned that Montenegro's membership would be met with unspecified retaliation.

NATO foreign ministers didn't appear to be phased. "This is the beginning of a very beautiful alliance," NATO chief Jens Stoltenberg said as Montenegro's foreign minister, Igor Luksic, walked into the NATO conference hall to applause. The government of Montenegro favors joining the alliance, but opinion is divided in the country, which split from Serbia in 2006 and was once part of Yugoslavia. Many residents are resentful that NATO bombed the country in 1999 as part of its air campaign to stop ethnic bloodshed in the Balkans. Montenegro is expected to become NATO's 29th member in about a year.