No matter the administration, NATO expansion never stops:

White House national security adviser Michael Flynn will recommend that President Donald Trump support allowing the small Balkan nation of Montenegro to join NATO, POLITICO has learned — despite strong opposition from Russia.

Bringing Montenegro into NATO is a pointlessmove, but it is a relatively harmless one. The alliance gains nothing from making Montenegro a member, and it takes on one more security dependent that we already know won’t pull its weight. Support for another round of expansion suggests that the new administration will be much more conventional in its support for NATO than Trump’s campaign rhetoric sometimes hinted.

Besides the fact that Montenegro adds almost nothing to the alliance, accession does not have broad support in Montenegro:

NATO accession is a highly controversial issue in Montenegro. An opinion poll conducted in December 2016 has only 39.5 percent of Montenegrins in favor of NATO membership and 39.7 against. Other opinion polls have suggested similar margins.

It doesn’t make sense to take in a new alliance member when there is no consensus in that country in favor of belonging to the alliance. NATO shouldn’t be adding new members in any case, but it certainly shouldn’t be taking in a country that doesn’t have a majority behind the idea of joining. At best, that will make Montenegro a half-hearted, grudging member, and at worst it makes it a real liability if there is a shift in public opinion against the alliance. I don’t think letting Montenegro join NATO makes any sense, but it certainly shouldn’t happen if it isn’t what most people in Montenegro want.