The North Atlantic Treaty Organization (NATO) summit in Brussels on June 14, 2021, offers an opportunity for the Alliance to send a clear message that its “open-door” policy remains firmly in place.

NATO has underpinned European and North American security for more than seven decades, so it is no surprise that many non-member countries in the transatlantic region want to join the Alliance. NATO’s open-door policy has been a crucial driver of modernization and reform in candidate countries, has promoted stability and peace in Europe, and has made it easier for the Alliance to coalesce around collective defense. The U.S. should continue to promote this important NATO policy.

The Open Door

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. Macedonia joined the Alliance in March 2020, bringing the total number of members to 30. This leaves two countries that are currently official candidates for joining NATO: Georgia and Bosnia and Herzegovina. Ukraine and Kosovo also hope to join the Alliance someday.

While Russia has described any further NATO enlargement as a “provocation,”REF no third party should have a veto over the decisions of the sovereign member states of NATO. It is for the democratic countries that make up the Alliance to decide whether to admit new members, and which ones. All decisions made by the Alliance require unanimity, including those regarding enlargement.

Georgia. Georgia was promised eventual membership at the NATO summit in Bucharest in 2008. Since then, not all members of the Alliance have been supportive. This is especially true of France and Germany, which blocked Georgia from receiving a Membership Action Plan (MAP).

After the Russian invasion in 2008 and the subsequent occupation of 20 percent of Georgia’s territory, Georgia has transformed its military and has been steadfast with its support for U.S.-led and NATO-led overseas security operations. Georgia has contributed thousands of troops to Iraq, and hundreds of peacekeepers to the Balkans and Africa. Perhaps Georgia’s greatest contribution was in Afghanistan.

Bosnia and Herzegovina. In April 2008, Bosnia and Herzegovina stated its desire to join NATO, and the country was offered its MAP in 2010. Bosnia and Herzegovina has made some progress in defense reform and has even deployed troops to Afghanistan, but the country is still far off from joining the Alliance.

In order to become a NATO member, Bosnia and Herzegovina must first register all immovable defense properties as state property for use by the country’s defense ministry. Little progress on this has been made. On a visit to Sarajevo in February 2017, NATO Secretary-General Stoltenberg stated that “NATO stands ready to activate your Membership Action Plan, once all immovable defence properties have been registered to the state. We welcome the reforms that you are making in the defence and security sector.”REF

An additional challenge is the internal politics of Bosnia and Herzegovina, which makes NATO membership controversial. This is especially true in the ethnically Serb region, now called the Republika Srpska, one of two sub-state entities inside Bosnia and Herzegovina that emerged from that country’s civil war in the 1990s. The Republika Srpska aligns more with Serbia and Russia’s position when it comes to Euro-Atlantic integration.

Ukraine. Even though NATO stated in 2008 that someday Ukraine would be invited to join the Alliance, until recently, the Ukrainians themselves have made little effort to help make this invitation a reality.

Once an aspiring NATO ally under the leadership of President Viktor Yushchenko, Ukraine’s previous pro-Russia government under President Viktor Yanukovich blocked membership progress. In 2010, the Ukrainian parliament passed a bill that barred Ukraine from committing to “a non-bloc policy which means non-participation in military-political alliances.”REF

In light of Russia’s aggression, the Ukrainian people have demonstrated, whether on the streets of the Maidan or through the ballot box, that they see their future allied with the West, not under Russian domination. While NATO should continue to foster closer relations with Ukraine, it is important to be clear that Ukraine has a long way to go before NATO membership becomes a serious possibility.

Kosovo. Many leaders in Kosovo have expressed a desire to join NATO over the past decade.REF In 2018, former Prime Minister Ramush Haradinaj stated that Kosovo would apply for NATO membership following the creation of its army.REF However, significant stumbling blocks remain before Kosovo can become a NATO member, not least of which is the fact that four current NATO members do not recognize Kosovo’s independence (Greece, Spain, Romania, and Slovakia).REF This reality foiled Kosovo’s attempts to join the Partnership for Peace.REF Without recognition from all NATO members, Kosovo will almost certainly be unable to become a NATO member.

A further stumbling block is the continued contentious relations between Kosovo and Serbia.REF While Kosovo is not yet ready to join the Alliance, the strategic review should keep open the possibility that it could join in the future. In the meantime, NATO should support Kosovo’s long-term transatlantic aspirations by being patient, supporting rule-of-law reforms in Kosovo, urging Kosovo’s army to adopt NATO standards, and encouraging normalization of relations between Kosovo and Serbia.REF

Action at the Summit

The upcoming Brussels Summit offers President Joe Biden an opportunity to send a clear message that the U.S. wants NATO’s “open-door” policy to remain firmly in place for those countries that meet the criteria set out in Article 10 of the North Atlantic Treaty. The U.S. can do this by:

• Making clear that Russia does not have a veto right. Russia should never be seen as having a veto over a country’s potential membership in NATO, including Ukraine. Just because a country was once occupied by the Soviet Union or under the domination of the Russian Empire does not mean that it is blocked from joining the Alliance in perpetuity.
• Ensuring that NATO meets with aspirant countries at the head-of-state level at the summit. In the past, this meeting has been relegated to foreign ministers. The NATO heads of state should make time to meet with the leaders of the two aspirant countries during the next NATO Summit. This would send the right message of support.
• Establishing realistic expectations for Ukraine. NATO should continue to foster Ukraine’s membership ambitions and keep the door open for eventual membership.
• Ensuring that Georgia continues to progress toward membership. The Alliance must be clear that Georgia’s successful completion of subsequent Annual National Programs, the close relationship through the NATO–Georgia Commission, and the Substantial NATO–Georgia Package are the true markers of progress that are bringing Georgia closer to membership.
• Supporting Bosnia and Herzegovina. With North Macedonia joining the Alliance in March 2020, Bosnia and Herzegovina remains the most realistic Balkan prospect to next join the Alliance. While there are many domestic political obstacles, such as the lack of support for membership by the Republika Srpska, NATO must keep the country on track for eventual membership.
• Encouraging Finland and Sweden to join NATO. Ultimately, the Swedish and Finnish populations will decide whether to join NATO, but privately NATO should pursue a policy that encourages membership for these two Nordic countries. Until they join NATO, they will not benefit from the Alliance’s security guarantee.
• Supporting Kosovo’s long-term transatlantic aspirations. While Kosovo is not yet ready to join NATO and has significant challenges to overcome, the Alliance should welcome Kosovo’s transatlantic aspirations, take a patient approach, and support modernization and key reforms.
• Taking a long-term and pragmatic approach with other European countries. In the early 1990s after the collapse of the Soviet Union, the idea of countries like Poland or Estonia joining NATO seemed unrealistic, if not crazy. Almost 30 years later, many of the countries of the former Warsaw Pact or those under Soviet occupation during the Cold War are now some of NATO’s most steadfast members. However unrealistic it might seem for a country like Belarus or Azerbaijan to someday join NATO, the world will be much different 50 years from now. The door must always be kept open, and policymakers must keep an open mind.

Key to European Stability

NATO has done more than any other organization, including the European Union, to promote democracy, stability, and security in the Euro-Atlantic region. This was accomplished by enticing countries to become a part of the club. While it may be tempting to view Montenegro’s accession to NATO as a closing ceremony for enlargement, that would be a substantial mistake. It is in America’s interest that NATO’s door remain open to deserving European countries.

Luke Coffey is Director of the Douglas and Sarah Allison Center for Foreign Policy, of the Kathryn and Shelby Cullom Davis Institute for National Security and Foreign Policy, at The Heritage Foundation. Daniel Kochis is Senior Policy Analyst in European Affairs in the Margaret Thatcher Center for Freedom, of the Davis Institute.