On June 25, outgoing NATO Secretary General Anders Fogh Rasmussen announced that there would be no enlargement at the next NATO summit in Wales in September 2014. This announcement was a huge disappointment for the Republic of Macedonia, which has met all criteria to join the alliance but continuously has its application vetoed by Greece over a name dispute.

Macedonia would be a welcome addition to the NATO alliance, and its membership would contribute to regional stability in southeastern Europe. The U.S. should continue to back Macedonia’s goal of joining the alliance.

Macedonia’s Long Road to Independence

The Republic of Macedonia is a small but geopolitically important Balkan nation. The region of modern-day Macedonia has been under the control of several regional empires throughout history. In antiquity, the kingdoms of Paeonia and then Macedon ruled the area. Later, numerous different empires and kingdoms ruled over this region, including the Roman, Byzantine, and Ottoman empires.

As the Ottoman Empire was slowly collapsing in the late 19th century, there was a rise in Macedonian nationalism seeking autonomy for an independent Macedonian state. Although this movement was successful for only a brief 12 days before the Ottomans took control again, it planted the seed for eventual independence. In the Balkan Wars of 1912–1913, this region was divided through the Treaty of Bucharest among Bulgaria, Greece, and Serbia.

In 1944, Macedonia became one of the six socialist republics of the Socialist Federal Republic of Yugoslavia. In 1990, after Yugoslavia changed from a socialist state to a parliamentary democracy, the word socialist was dropped from Macedonia’s name. With the dissolution of Yugoslavia in 1991, Macedonia became an independent state and kept the name—Republic of Macedonia—as its new constitutional name. Greece quickly protested on the grounds that the name Macedonia, which is the same as that of Greece’s northern province, implied regional territorial claims by the new nation. This claim is unfair for three reasons:

Macedonia is the size of Vermont and has a population of only 2 million. Greece has a population of 11 million and is five times larger. Macedonia does not pose a military threat, either practically or rhetorically, to any of its neighbors—especially Greece. Although there is nothing indicating that in the 21st century any of Macedonia’s neighbors have territorial designs on Macedonia, historically regional powers sought to control Macedonia, not the other way around. This was the primary driver of the 1912–1913 Balkan Wars, for example. To alleviate Greece’s concerns, a specific provision has been placed in Macedonia’s constitution stating: “The Republic of Macedonia has no territorial pretensions towards any neighboring state.”

Believe It or Not, It’s All About a Name

In 1993, Macedonia joined the United Nations under the provisional name “the former Yugoslav Republic of Macedonia.” In 1995, Macedonia and Greece agreed to a U.N.-brokered interim accord in which Athens agreed not to block Macedonia’s integration into international organizations such as NATO so long as it called itself “the former Yugoslav Republic of Macedonia” until both sides agreed on a mutually acceptable name.

Macedonia joined NATO’s Partnership for Peace in 1995 and received a Membership Action Plan in 1999. Upon completing its Membership Action Plan in 2008, Macedonia anticipated an invitation to join the alliance at the NATO summit in Bucharest. Yet Greece unilaterally vetoed Macedonia’s accession over the name issue. In December 2011, the International Court of Justice ruled that Greece’s veto was in blatant violation of the 1995 interim accord.

Macedonia has little leverage in urging Greece to come to the bargaining table. Greece is already a NATO member, and Athens’s internal political dynamics are likely to delay the negotiation process.

Macedonia: A Solid U.S. Ally

Despite the small size of Macedonia’s military (approximately 7,300 service members as part of a Joint Operational Command), the nation has already contributed respectably to the NATO alliance. Macedonia has participated in the International Security Assistance Force (ISAF) mission in Afghanistan since 2002, rotating a total of 3,200 troops to Afghanistan during this period. Furthermore, Macedonia has indicated its willingness to participate in the post-2014 follow-on mission to train and assist Afghan forces after ISAF’s combat mission ends.

Macedonia sends forces to Bosnia and Herzegovina as part of the EU’s Operation Althea. Since 1999, it has allowed NATO forces deploying to Kosovo to transit its territory. Further afield, Macedonia participates in the U.N. Interim Force in Lebanon, and between 2003 and 2008 it deployed forces in support of U.S.-led operations in Iraq, including a special operations unit. These contributions demonstrate a willingness by Macedonia to contribute to global security.

It is important for the U.S. and NATO to ensure that NATO enlargement takes place for those countries that meet the high standards. NATO’s “open-door policy” is critical to mobilizing Europe and its allies around collective transatlantic defense. The open-door policy also promotes democracy, stability, and security in the North Atlantic region by enticing countries to become a part of the alliance through positive democratic and military reforms. If aspiring NATO members see the door closed for Macedonia, it could discourage them from undertaking the desired democratic reforms to someday join the alliance themselves.

Backing Macedonia Is the Right Thing

The U.S. should make sure that the open-door policy is not closed. Macedonia met all criteria to join NATO in 2008. The only thing preventing Macedonia from joining the alliance—and therefore preventing the Wales summit from being an enlargement summit—is Greece’s veto. Keeping the door closed to Macedonia does not benefit Europe’s security and it weakens NATO’s open-door policy as a tool for reform, modernization, and democratization.

To send the right messages, the U.S. should:

Show support for Macedonia. The U.S. should use the NATO summit to show its appreciation for Macedonia’s contributions to ISAF and thank the Macedonian people for their patience while they wait to join the alliance six years after meeting all the criteria.

The U.S. should use the NATO summit to show its appreciation for Macedonia’s contributions to ISAF and thank the Macedonian people for their patience while they wait to join the alliance six years after meeting all the criteria. Privately pressure Greece. The U.S. should pressure Greece behind the scenes to allow Macedonia to join NATO under the terms of the 1995 interim accord.

The U.S. should pressure Greece behind the scenes to allow Macedonia to join NATO under the terms of the 1995 interim accord. Ensure that NATO is clear on Macedonia’s future membership. The summit declaration should make it clear that it is the official position of NATO that Macedonia’s future is in the alliance.

The summit declaration should make it clear that it is the official position of NATO that Macedonia’s future is in the alliance. Continue working with the Macedonian armed forces. As the NATO-led combat mission in Afghanistan comes to an end, the U.S. should ensure that it continues to train with and prepare the Macedonian military for future challenges.

NATO’s Open-Door Policy Jeopardized

Enlargement of the alliance has greatly contributed to the security of all the member states and regional stability. The U.S. should work to ensure that NATO’s open-door policy remains in force and that qualified nations are allowed a timely accession to the alliance.

Greece’s pertinacious opposition over the name issue, coupled with the illegality of its position under international law, has jeopardized NATO’s open-door policy. Greece should work with Macedonia to seek reconciliation, and the U.S. should play a leading role.

—Luke Coffey is Margaret Thatcher Fellow in the Margaret Thatcher Center for Freedom, of the Kathryn and Shelby Cullom Davis Institute for National Security and Foreign Policy, at The Heritage Foundation.