The global security architecture entered a major restructuring process in the mid-2020s. Russia’s invasion of Ukraine, China’s rising global influence, and international terrorist threats have profoundly affected not only the North Atlantic Treaty Organization’s (NATO) foreign policy and deterrence strategies but also the alliance’s internal structural dynamics. As of 2026, reports and analyses evaluating NATO’s performance show that, although the alliance has strengthened its defense capabilities, it increasingly displays a fragmented Picture in terms of strategic and political cohesion. Understanding NATO’s current state requires examining not only military expenditure figures but also member states contribution levels, burden-sharing, and tension within transatlantic relations.
In recent years, one of NATO’s most important agenda items has been burden-sharing. Historically, a defense spending target of 2 % of Gross Domestic Product (GDP) has been set, which stands out as a parameter through which the alliance seeks to establish the principle of equitable responsibility among its members.[1] In 2025, European countries and Canada increased their defense expenditures by an average of 20% this can be interpreted as a direct result of both the heightened threat perception following Russia’s attack on Ukraine and the longstanding message from the United States that Europe must assume greater responsibility. However, this increase has revealed significant differences among alliance members.[2]
According to NATO’s latest assessment report, differences in defense spending within the alliance stand out prominently. Class A, or the Teacher’s Pets category, encompasses frontline countries bordering Russia. Poland at 4.3% and Lithuania at 4% bear the alliance’s defense burden most heavily, while Latvia at 3.7%, Estonia at 3.4%, Denmark at 3.3%, and Norway at 3.2% stand out for their high contributions in terms of strategic deterrence and operational capacity. These countries distinguish themselves not only through financial contributions but also through frontline duties that directly reinforce NATO’s credibility. Class B, or the “Above Average” category, includes Finland at 2.9%, Greece at 2.8%, the Netherlands at 2.6%, Sweden at 2.5%, Germany at 2.4%, and Turkey at 2.3 %; these countries meet their burden-sharing obligations without facing the strategic risks encountered by frontline states. The United States, at 3.2% of GDP, is also classified in Class B; however, it shows a slight decrease compared to 2024, highlighting the growing need for European responsibility and raising transatlantic tensions.[3]
Countries in Classes C and D present a more problematic Picture in terms of the alliance’s burden- shraing. Class C, or the ‘Barely Scraping By’ category, includes the United Kingdom, Romania, North Macedonia, Luxembourg, Bulgaria, Croatia, France, Slovakia, and Montenegro, while Austria, Slovenia, Italy, Albania, Belgium, Canada, Portugal, and Spain are only able to meet the 2% target. Although some of these countries have recorded notable annual increases, their contributions remain limited in terms of strengthening the alliance’s strategic deterrence capacity. Class D, or the ‘The Truants’ category, includes Hungary at 2.1% and the Czech Republic at 2%; their expenditures are on a declining trend, and they are considered weak links within the alliance in terms of security. This situation highlights that burden-sharing extends beyond financial contributions to include operational and strategic dimensions as well.[4]
This divergence in defense expenditures is of critical importance for NATO’s stretegic governance. The United States pivot to the Asia-Pacific and its increasing demands for greater European contributions necessitate a reconsideration of the alliance’s internal distribution of power. In this contest, the conceptualizations of NATO 3.0 denote the alliance’s transition from the crisis management-oriented NATO 2.0 phase of the post-Cold War era to a new period centered on 3.0, thus represents not only a military doctrinal update but also a phase in which burden-sharing is redefined, and Europe is expected to enhance its defense capabilities.
In this process, the strengthening of Europe’s own defense capabilities requires not only increased budgetary allocations but also coordinated industrial policies, joint procurement mechanisms, and expedited decision-making processes.[5] Nonetheless, political divergences and varying strategic priorities within the alliance impede the development of this capacity. For example, member states display divergent attitudes toward external actors such as Russia and Iran, with some European countries aligning closely with U.S. politicies, while others adopt a more independent approach. Recent divergent assessments regarding Iran highlight how sensitive achieving strategic cohesion within the alliance has become.[6]
These divergences within NATO also affect the alliance’s external deterrence capability. The lack of a common strategic vision toward actors such as Russia and China slows decision-making processes and complicates coordination. Moreover, the alliance’s operational effectiveness depends not only on military capabilities but also on political consensus. In particular, unanimity-based decision-making mechanisms can sometimes prove ineffective due to strategic differences among members. This situation demonstrates that NATO is tested not only as a military alliance but also as a political organization.
NATO’s overall performance does not point to an entirely negative picture. Increase in defense spending, particularly the proactive policies of European countries, and contributions from Canada, indicate that the alliance’s capabilities are being strengthened. For instance, the 20% increase in European defense spending represents a transformation aimed both at deterring the Russian threat and at alleviating the strategic burden on the United States. Moreover, NATO is developing a new deterrence capability on its eastern flank through proactive defense initiatives and operational mechanisms such as “Sentry”. This demonstrates that the alliance is moving toward a preventive security strategy, rather than remaining purely reactive.[7]
However, in the long term, NATO’s sustainability will depend not only on its military capabilities but also on Europe’s political cohesion and industrial infrastructure. European countries that are increasing defense spending also face the challenge of developing a coordinated production capacity and technological infrastructure. Otherwise, rising budgetary and capability targets may prove ineffective due to logistical and industrial bottlenecks. This underscores that the success of NATO 3.0 requires an integrated approach, both economically and militarily.
As of 2026, NATO’s record is highly multifaceted. While frontline states and some Class B members successfully shoulder the alliance’s security burden, certain other members lag behind. The relative decline of the United States and the increasing need for European responsibility are generating new tensions in transatlantic relations. NATO 3.0 represents not only a period of military modernization but also one in which burden-sharing is being redefined, and Europe’s capacity for more independent action and political cohesion is being tested. In this context, the future of the alliance will be shaped not only by military strength but also by strategic cohesion, industrial capacity, and political will. The fundamental question facing NATO is whether it will become a stronger military alliance in the face of growing threats or a loose coalition of members with divergent priorities; the answer will determine the future not only of NATO but also of the Euro-Atlantic security architecture.
[1] “NATO hits 2% defence target, but some members risk falling behind”, Caliber, https://caliber.az/en/post/nato- hits-2-defence-target-but-some-members-risk-falling-behind, (Date Accessed: 27.03.2026)
[2] Mark Hallam, “European NATO defense spending rose by almost 20% in 2025”, DW, https://www.dw.com/en/european-nato-defense-spending-rose-by-almost-20-in-2025/a-76544678, (Date Accessed: 27.03.2026).
[3] Victor Jack, “NATO report card: Who gets a gold star and who gets detention?”, Politico, https://www.politico.eu/article/nato-report-card-who-gets-a-gold-star-and-who-gets-detention/, (Date Accessed: 27.03.2026).
[4] Ibid.
[5] Burak Bir, “UK urged to prepare for European-led NATO amid US uncertainty”, Anadolu Ajansı, https://www.aa.com.tr/en/europe/uk-urged-to-prepare-for-european-led-nato-amid-us-uncertainty/3881646, (Date Accessed: 27.03.2026).
[6] Dr. Cherkaoui Roudani, “Iran Isn’t Just a Threat—It’s Splitting NATO”, Modern Diplomacy, https://moderndiplomacy.eu/2026/03/29/iran-isnt-just-a-threat-its-splitting-nato/, (Date Accessed: 27.03.2026).
[7] Ibid.
