The Senate will likely soon consider whether or not to approve the accession of the Balkan nation of Montenegro to join the North Atlantic Treaty Organization (NATO). While small, Montenegro sits in a geographically important region and has proven itself a worthy partner to the U.S. Furthermore, it has carried out essential reforms and contributed to NATO-led missions. Montenegro’s NATO membership would serve U.S. interests by helping stabilize the region and by strengthening the alliance.

Montenegro’s admittance is a critical test of the alliance’s open door policy, which has been a pillar of NATO since its inception. Russia has worked hard to keep Montenegro from becoming NATO’s 29th member state, exerting outsized influence to stop its membership bid. Backing Montenegro’s membership is not only the right thing for the Senate to do, it would send a clear signal that no third party has a veto over NATO enlargement decisions.

NATO Enlargement Is Important

For almost 70 years, NATO has served as the bedrock of transatlantic security, with myriad benefits for the United States. NATO’s open door policy for qualified countries has contributed greatly to transatlantic security since the first round of enlargement in 1952, helping to ensure the alliance’s central place as the prime guarantor of security in Europe. The North Atlantic Treaty’s Article 10 states that any European State that is “in a position to further the principles of this Treaty and to contribute to the security of the North Atlantic area”[REF] can be invited to join the alliance. While Russia has described any further NATO enlargement as a “provocation,”[REF] no third party should have a veto over the decision of the sovereign member states of NATO.

Montenegro joined the Partnership for Peace Program in 2006 and expressed a formal interest in joining the alliance in 2008. Montenegro began a Membership Action Plan (MAP) in 2009, the first of three MAP cycles. On May 19, 2016, Montenegro and NATO foreign ministers signed an accession protocol, and Montenegro became an invitee nation, which allows officials from the nation to take part in NATO meetings as observers. All 28 NATO member states must ratify the accession protocols before Montenegro attains full membership.

NATO enlargement has helped bind likeminded democracies on both sides of the Atlantic in mutual self-defense. Furthermore, requirements for joining the alliance have proven to be critical catalysts for reform, particularly reforming the military and strengthening the rule of law in candidate countries. Speaking in May, Montenegrin Defense Minister Pejanović Đurišić highlighted her nation’s readiness: “We have shown that Montenegro has the required capacities, recognizes the true values and has sufficient dedication to be a credible and reliable partner.”[REF]Montenegro has fulfilled the requirements of NATO membership and its potential accession is a crucial test of the principle of the open door policy.

A Commendable Partner for the United States and a Contributor to the Alliance

Montenegro is a small but geopolitically important Balkan nation, situated in a region of Europe that has more than once drawn U.S. service members into combat. NATO has helped stabilize a region with a history of inter-ethnic strife; Montenegro’s membership would further improve the stability of the region. Montenegro is also close to important U.S. bases, including Naval Air Station Sigonella in Italy, which hosts P-8 sub-hunting planes that patrol the Mediterranean, and the U.S. Naval Base at Souda Bay, Greece, which hosts the NATO Missile Firing Installation, the only location in Europe where the alliance can test-fire missiles.c Currently, the Balkan nations of Albania and Croatia are NATO members, and Bosnia and Herzegovina and Macedonia are candidate countries.

Montenegro’s military is relatively small, but it has already proven itself a worthy partner for the U.S. Montenegrin troops took part in NATO’s International Security Assistance Force mission in Afghanistan from 2010–2014, and its men and women in uniform continue to contribute to the follow-on Operation Resolute Support, helping to advise, train, and assist Afghan security forces. Montenegro has donated 1,600 weapons and 250,000 rounds of ammunition to the Afghan National Army.[REF] This November, Montenegro hosted CRNA GORA 2016, a NATO civil-emergency response exercise. In addition, Montenegro has been part of the State Partnership Program since 2006, partnering with the Maine National Guard.

Speaking in December, NATO Secretary General Jens Stoltenberg underscored the benefit of Montenegro’s membership in the alliance:

NATO membership is not only good for Montenegro, but it’s also good for NATO in the way that Montenegro contributes to our collective defense and to the security of the whole Alliance, by its strategic location where they are close to the Adriatic Sea and by bringing partnerships into the Alliance and also by the fact that Montenegro has some military capabilities which are important also to NATO. [REF]

Moscow Going to Great Lengths to See Montenegro’s Bid Fail

Russia has sought to expand its influence in the Balkan region. It has significant economic influence in Montenegro, and in 2015, unsuccessfully sought access to Montenegrin ports for the Russian navy to refuel and perform maintenance. Unhappy with Montenegro’s decision to join NATO, Russia stands accused of being behind a failed plot to break into Montenegro’s parliament on Election Day, assassinate its former prime minister, and install a pro-Russian government. While Russia has denied involvement in the plot, Montenegro’s chief prosecutor has named two Russian citizens as the alleged organizers, saying the plot was the work of “nationalists from Russia.”[REF]

The murky coup plot appears to be the latest example of Russia’s use of irregular warfare to achieve its desired outcomes. In Montenegro, this means putting a stop to the nation’s accession to NATO and getting rid of a ruling party that has steered the nation in a pro-West direction. It also underscores the geopolitical importance Russia places on the Balkan region. Despite the pressure, Montenegro’s new Prime Minister, Dusko Markovic, reiterated that Montenegro is committed to joining NATO, telling a session of parliament in November that the “Cabinet that you will vote for today will take us to NATO.”[REF]

Signals of the United States’ commitment to Europe will be watched for closely. Therefore, Congress should:

Demonstratively reaffirm commitment to NATO’s open door policy. For nearly seven decades, NATO enlargement has been an integral component of the alliance’s strength.

Recognize Montenegro’s contributions. A worthy partner for the U.S., Montenegro continues to contribute to NATO-led missions, and would be a benefit to the alliance as a member.

Make clear that Russia does not have a veto right. Clearly articulate that no third party has a veto over NATO enlargement.

Do the Right Thing

Granting Montenegro NATO membership is the right thing to do. The nation has carried out essential reforms, withstood Russian pressure, and proven itself a worthy partner and willing contributor to NATO missions. Its inclusion in the alliance will strengthen NATO and contribute to regional stability. Montenegro’s inclusion also sends a message of strength to Russia and makes clear to our European allies that the U.S. remains as committed as ever to transatlantic security.