Moscow has issued its strongest warning yet over the prospect of Montenegro becoming a full member of NATO. The Russian State Duma addressed a statement to the parliamentary assemblies of NATO and OSCE countries, as well as to the national parliaments of the Balkan states, warning of the possibility of "a new Cold War."

Duma deputies are “seriously concerned about the policy of Montenegro’s integration into NATO,” which, they reportedly argue, threatens to rend Montenegrin society and ratchet up social and political tensions.

The Russian parliamentarians' statement can be seen as a direct response to an open letter published on June 20 by senior U.S. officials and military leaders. They urged the White House and Congress to formally approve Montenegro's accession to NATO by 2017, saying the Balkan country's membership would promote "stability and security in Southeastern Europe." The signatories of that letter include former U.S. Defense Secretary Chuck Hagel and two former NATO supreme commanders in Europe -- U.S. General Philip Breedlove and U.S. Admiral James Stavridis. They said that Montenegro has “built a small but capable military and reformed its security services to meet NATO standards” and “made significant progress” on rule of law, corruption, and organized crime.

Moscow's most recent denunciation of Montenegro's pending NATO membership comes after a series of threats and protests organized in Podgorica by a small but vocal Russian-sponsored opposition party. Speaking at the St. Petersburg Economic Forum, Russian President Vladimir Putin said: "The Soviet Union has collapsed, and the Warsaw Pact no longer exists, but NATO is still approaching our borders. It is hard to understand why Montenegro would want to join the alliance. Where is the threat coming from? There is an absolute disregard for our position [on this matter]."

Commenting on the Russian campaign against Montenegro's NATO membership, Montenegrin lawmaker Nikola Gegaj told RFE/RL in Podgorica that he was surprised at the blunt tone of the criticism from Moscow.

"I think this reaction is not expected from such a large and powerful country -- a country with a great tradition and culture," Gegaj said. "It is hard to understand, especially if we keep in mind that the criticism is directed at the smallest country in the region."

On a recent visit to Montenegro, I spoke to Zarko Radulovic, the manager of the luxury Hotel Splendid in the coastal town of Budva. He said of anti-NATO demonstrations organized by pro-Russian groups in Podgorica: "Russia does not understand the Balkans. [Russians] have chosen the wrong players. They have aligned themselves with people without substance or local influence. Otherwise, we would have reasons to be concerned."

Explaining why he believes he can be trusted on the issue, Radulovic pointed to his background: "My own father was imprisoned for supporting Stalin. He was a Russophile and he was accused of being a traitor to his own people. My first wife was Russian. My second wife is Russian. And yet I support Montenegro's NATO membership with all my heart."

I asked him what Montenegro might expect to get from joining NATO.

"For the first time in our history, we would be in the company of the most civilized nations," he answered.

In the opinion of this successful Montenegro entrepreneur, smaller is better. He is not concerned that Montenegro has a population of just 600,000.

On the contrary: "It is an advantage," he said. "We only need strong and sincere partners. In a small country, whatever problem you have can be fixed in a week."

Around one-third of Montenegro's inhabitants are ethnic Serbs and most of them oppose NATO membership.

A formal invitation was issued by the alliance on December 2. Final accession talks were concluded in May, allowing Montenegro to assume "observer" status pending ratification by the governments of the other members, as well as by Montenegro's own parliament. Ratification by each member state is expected to be completed by spring 2017.