The US Senate just dealt Russia a big blow in the Balkans

The US Senate voted overwhelming to approve Montenegro's ascension into NATO - the most powerful military alliance in the history of the world and the explicit enemy of Russia.

The landslide 97-2 vote on Tuesday may demonstrate the willingness of senators to stick it to Russia, as the Kremlin's meddling in the US elections and possible collusion with US President Donald Trump's 2016 campaign continues to make daily headlines, but Trump's own Secretary of State Rex Tillerson pushed for Montenegro's ascension.

This contrasts sharply with a popular media narrative that the Trump administration favors Russia, and seemingly even Trump's own campaign sentiments towards the alliance, which he repeatedly derided as "obsolete."

"Montenegro is a small country with half the population of Fairfax county," the Atlantic Council's Jorge Benitez told Business Insider. Though Montenegro has a "very strategic location in southeast Europe" along the Adriatic sea, it's the exact kind of NATO member Trump sharply criticized.

NATO asks its members to contribute 2% of their GDP to defense spending. For Montenegro, that would have meant a contribution of less than $80 million in 2015 - about the price of a single F-18 Super Hornet - while adding another 5,300 square miles for the alliance to defend.

So while NATO stands to gain little militarily from the small Balkan state, it stands to anger Russia monumentally, according to Benitez, who said that Russia describes NATO as the enemy in its internal military communications.

In fact, Montenegro meant so much to Russia that Russian agents allegedly tried to have the prime minister killed in an attempted coup, according to assessments from international intelligence agencies.

Of course, the US Senate alone doesn't decide who gets to be a NATO member. The legislatures of the other 28 NATO members will have to weigh in as well.

But for now, it seems like Trump's administration has embraced the alliance.