The North Atlantic Treaty Organization has underpinned the security of Europe and North America for more than 70 years, so it is no surprise that many of the countries in the transatlantic region that are not already members want to join the alliance. NATO’s open-door policy has been a crucial driver of modernization and reform in candidate countries. It has promoted stability and peace in Europe and has made it easier for the alliance to coalesce around collective defense. Article 10 of the 1949 North Atlantic Treaty — the alliance’s founding document — says 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” can be invited to join the alliance. The 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. NATO was established in 1949 with 12 members and a mission to deter, and if necessary defeat, Soviet aggression in Western Europe. By the time the Cold War ended in 1990, NATO had grown to 16 members. Between 1990 and 2004, the alliance added 10 new members, mainly from the former Warsaw Pact in Eastern Europe. Since 2004, however, only four more countries have joined. The most recent, North Macedonia, joined in March 2020, bringing the total membership to 30. Currently, four countries in Europe hope to join the alliance someday. Georgia and Ukraine were promised eventual membership at the NATO summit in Bucharest in 2008. Since then, however, not all members have been supportive and progress has been slow. Both countries have made tremendous reforms to their armed forces. Relations between NATO and Tbilisi and Kyiv have also become closer over the years. However, both have experienced Russian invasions, which has all but stopped meaningful progress toward attaining full membership. In fact, the question of future Ukrainian membership of NATO is one of the main factors in the recent rise in tensions in Eastern Europe. In April 2008, Bosnia and Herzegovina also expressed its desire to join NATO. While some progress has been made through defense reforms, it is still some way off from joining. NATO has done more than any other organization, including the EU, to promote democracy, stability, and security in the Euro-Atlantic region. It accomplished this by enticing countries to become a part of the club. Luke Coffey One major challenge is the internal politics of Bosnia and Herzegovina, which makes membership of NATO controversial. This is especially true in the country’s ethnically Serb region, Republika Srpska, one of two sub-state entities within Bosnia and Herzegovina that emerged from the civil war in the 1990s. Republika Srpska aligns more closely with neighboring Serbia, which remains suspicious of closer relations with NATO due to the 1999 Kosovo War. Finally, there is Kosovo. Over the past decade, many of its leaders have expressed a desire to join NATO. Significant stumbling blocks to this remain, not the least of which is the fact that four NATO members — Greece, Romania, Slovakia and Spain — do not recognize Kosovo’s independence. In addition to Georgia, Ukraine, Bosnia and Herzegovina, and Kosovo, two other countries easily meet the criteria to join but, for geopolitical reasons, have chosen not to: Sweden and Finland. Both enjoy a very close relationship with NATO and there are many members that would happily admit both. Ultimately, the Swedish and Finnish people will decide whether or not they want to join NATO. While public opinion is slowly moving toward support of membership, it is unlikely that either country will join anytime soon. Of course, regardless of how close to NATO they are, until Sweden and Finland formally joins the alliance, they will not benefit from its security guarantee. Sadly, the expansion of the alliance is not getting much attention within NATO. Part of the reason for this is that the process of adding new members can be complex and, at times, contentious. Admitting new countries from the Eastern Bloc was relatively straightforward in the 1990s. Today, countries such as Georgia and Ukraine bring complex geopolitical baggage with them. NATO policymakers would rather ignore the complicated issue than pursue a genuine policy of enlargement. However, the concept of adding new members into NATO is enshrined in the alliance’s founding treaty. As NATO undergoes its first strategic review in more than a decade, there is an opportunity for the alliance to send a clear message that its open-door policy remains firmly in place. In doing so, it must make clear that no third party should have a power of veto over the decision of a sovereign country to join NATO or not. Also, it is for the democratic countries that make up the alliance, and nobody else, to decide on whether to admit new members, and which ones. NATO has done more than any other organization, including the EU, to promote democracy, stability, and security in the Euro-Atlantic region. It accomplished this by enticing countries to become a part of the club. While it might be tempting to view North Macedonia’s recent accession to NATO as a closing ceremony for enlargement, that would be a substantial mistake. It is in NATO’s best interests that its doors remain open to deserving European countries. Ultimately, this is the best path to peace and prosperity in the transatlantic community. Luke Coffey is the director of the Douglas and Sarah Allison Center for Foreign Policy at the Heritage Foundation. Twitter: @LukeDCoffey Disclaimer: Views expressed by writers in this section are their own and do not necessarily reflect Arab News" point-of-view