NATO has invited Montenegro to join the alliance:

For the first time in six years, NATO on Wednesday invited a new member to join the military alliance, prompting a heated response from Russia and further underscoring escalating tensions between the Cold War adversaries.

The latest addition to NATO isn’t as dangerous or provocative as trying to add members from the former Soviet Union or along Russia’s borders, but bringing Montenegro into the alliance is still a mistake. Montenegro adds nothing to the alliance, and will become one more ally dependent on the U.S. It will be another member that won’t do enough to contribute to the alliance, and it will make an already large, unwieldy organization even more so. There is no security threat that NATO will be better able to address because it has gained Montenegro as a member, and the alliance isn’t protecting Montenegro from anything because there is no threat to the country. This is latest expansion of NATO may be its most unnecessary one yet. Insofar as adding one more member to the alliance makes it harder to reach consensus on anything, further NATO expansion makes the alliance even less effective than it is now.

Russia is objecting to the inclusion of Montenegro as it always does with each round of expansion, but unlike proposed membership for Ukraine or Georgia I suspect that this expansion doesn’t really alarm or anger Moscow that much. They are denouncing it because they feel obliged to denounce any and all NATO expansion, but unlike with these other countries Montenegrin membership isn’t likely to set off a new crisis. That doesn’t make the latest expansion a good idea, but it is a less foolish than trying to continue the alliance’s eastward expansion.