For two years, Russia has launched constant air and missile attacks against Ukraine, featuring thousands of ballistic, cruise, and hypersonic missiles, unguided rockets and bombs, and one-way attack drones. So it’s no surprise that at the recent 75th anniversary of NATO, the allies paid close attention to their air and missile defense capabilities.

NATO member states have made some progress in addressing their own air defense weaknesses. The allies, for example, now recognize their low capacity in low-altitude sensors and missile interceptors and are investing in their defense industrial base and in off-the-shelf technologies. The alliance has also expanded its focus from defeating enemy aircraft and cruise missiles to defending against a wider spectrum of threats, including ballistic missiles and small drones.

Yet cracks and shortfalls remain. Notable policymakers, scholars, and military officers continue to critique the broader framework in which allies research, develop, acquire, and deploy air and missile defenses on a largely ad hoc, country-first basis. States may coordinate across these functions as they see fit, and often do consider the benefits of common or interoperable platforms before moving to buy them. Yet critics say — more rightly than not — that the current federated approach prioritizes domestic politics and economic interests over allied cooperation and interoperability. NATO allies, they argue, should do more to integrate their air defenses into a stronger, collective architecture.

Three visions for NATO air and missile defense emerge from these critiques and ensuing debates. One aspires for greater NATO involvement in allied air defense development and deployment plans. It requires the most political and financial support but offers significant military benefits. Another aims for Europe to expand air defense procurement of common systems to quickly boost defenses, create economies of scale, and improve allied interoperability. A third vision predicts that a federated approach to air defense will continue for years to come, but suggests that NATO can do more at the margins to encourage air and missile defense coordination.

These visions are distinct but not mutually exclusive, each with their respective strengths and weaknesses. NATO and national political leaders should consider these paths to improve allied air defense capabilities and reduce costs. At the same time, they should also encourage greater allied air defense cooperation in the near term by publishing their goals, studying lessons learned, and clarifying priorities.

Establishing NATO Standards and Plans

To follow this debate, one must first appreciate that “integration” is the favorite word of air defenders. Their mission requires operators, sensors, interceptors, and command and control facilities spread across various geographies to coordinate closely to be effective. When a radar detects a foreign object, air defenders must forward tracking data to a command and control node where staff develop and distribute a common air picture. This connectivity helps all air defenders better evaluate incoming threats and their potential targets. Air defenders must also coordinate on how to most efficiently employ defensive counterair or limited and costly missile interceptors to mitigate incoming threats. More integration and interoperability — for both data sharing and tactical procedures — simplify operational requirements and facilitate cooperation in training, maintenance, and logistics.

The desire for greater air and missile defense integration has led to proposals that NATO take a more active role in allied air defense development and deployment plans. In this vision, NATO may promote technical standards for air defense software, similar to agreed upon standards for 5.56×45 millimeter ammunition. In theory, nonproprietary software that permits cross-platform communications could allow any sensor to work with any interceptor — French SAMP/T radars, for example, could direct U.S. Patriot missile engagements. NATO could similarly share standards for tactics, techniques, and procedures to support seamless interactions among air defenders themselves. NATO might also expand air defense deployments in the Baltics or across the eastern front on a permanent or rotational basis. Some of these suggestions reinforce the current NATO Integrated Air and Missile Defense mission, while others go beyond it.

A 2021 RUSI report entitled The Future of NATO’s Air and Missile Defence presents the clearest sketch of this vision. It argues that NATO air defense must “go through a process of rationalisation and integration, resulting in an Alliance-wide capability that addresses the spectrum of potential antagonists’ threats.” A recent NATO report alludes to similar reform, asserting that NATO must integrate its defenses into a “new architecture” that is “fit for purpose for the rapidly evolving environment facing NATO.” Neither report lays out precisely who is responsible for designing this new air defense architecture; the RUSI report, however, repeatedly points to the centralized NATO Ballistic Missile Defense program as a model to emulate.

Of the three visions for air and missile defense, the NATO-led approach is the most expansive. Wide compliance on technical standards would fuel air defense cooperation and interoperability. Joint deployments could strengthen defenses where they are most needed. Yet implementing this vision would require major shifts in how NATO allies approach air and missile defense.

The potential drawbacks are clear. First, a NATO-designed architecture could be politically unpopular. Buying air and missile defense to protect domestic citizens is generally acceptable. Buying and deploying defenses to better protect the wider European continent is probably less so, as suggested by the growing reluctance to provide military aid to Ukraine. Nationalism still matters. There is a reason the first stated priority of U.S. missile defense is always to defend the homeland (even when that’s not what gets funded in practice).

Second, establishing NATO standards for air and missile defense is hard. It is unclear how long such a process would take at the negotiating table, or if the desired level of interoperability would require developing air defenses or sensors from scratch. As one NATO official said last year, “Having a standard is one thing, meeting a standard is something altogether different.” There is also the matter of transitioning operators from non-interoperable legacy defenses to new platforms and procedures.

Third, NATO’s cooperative initiatives typically require large U.S. contributions. When advocates for a NATO-designed architecture argue that the NATO ballistic missile defense system is a model to emulate, they sometimes omit that the United States has, between 2011 and 2023, spent approximately $2.3 billion to field the European Phased Adaptive Approach. This initiative forms the backbone of NATO ballistic missile defense. First announced in 2009, the European Phased Adaptive Approach includes a U.S. AN/TPY-2 radar in Turkey, four Aegis ships operating in the Mediterranean and homeported in Spain, a command and control node in Germany, and Aegis Ashore sites in Romania and Poland. This is a significant undertaking by one country. The program supports U.S. security interests in Europe, but at a time when a popular American political movement is criticizing U.S. spending on behalf of its allies, moving further in this direction is politically precarious.

In sum, a NATO-designed architecture offers significant benefits for allied air and missile defense. Yet advocates may underestimate the political difficulties of having member states shift resources from national to continental defense, or reformatting defense production lines to follow NATO standards. The NATO ballistic missile defense system commonly used as a model for cooperative defense is a program for which the American taxpayer is footing most of the bill. A similar funding approach is unlikely to work here.

Boosting European Procurement

European leaders have made alternative proposals centered on increasing the size and strength of Europe’s air and missile defenses. Their key objective: Buy more, buy the same. There are multiple variants of this vision, with differences across political ambitions, timelines, platform interoperability, and Europe’s salience. All are intended to support NATO air and missile defense requirements — not to replace NATO’s role. The two most frequently discussed positions are the German-led European Sky Shield Initiative and the yet-unnamed French perspective on E.U.-centric air defense.

Launched in 2022, the European Sky Shield Initiative offers a new vehicle for European governments to buy off-the-shelf air and missile defenses at a time when their current inventory is small and weak. It also enables cost savings by creating economies of scale through multinational acquisitions of common defenses, namely the German IRIS-T, U.S. Patriot, and Israeli Arrow-3. Under the European Sky Shield Initiative, as the Swiss government explains, “Each participating country can define where and to what extent it participates.” The framework is thus open to all but required of none. It has pushed significant investments including a joint plan for Germany, the Netherlands, Romania, and Spain to buy up to 1,000 Patriot missiles.

French President Emmanuel Macron offers an alternative vision for European procurement. He argues that Europe should not rely on non-European products like the Patriot or Arrow-3 because they are “less manageable” and “subject to timetables, priorities, and sometimes even authorizations from third countries.” Rather, France calls for Europe to develop and procure its own defenses to support the European defense industrial base. This fits within wider political plans for Europe to reestablish its industrial capacity and regain “strategic autonomy” over its foreign policy.

Whether it’s through the German-led European Sky Shield Initiative, the French alternative, or otherwise, boosting European procurement can support NATO air and missile defense objectives. These programs, however, may continue to prioritize national political and economic interests over allied cooperation and interoperability. This is demonstrated in Germany’s acquisition plan. Berlin chose the Arrow-3 over Terminal High Altitude Area Defense, despite the latter already being integrated with their Patriot defenses and the broader NATO air and missile defense architecture. It is rumored that this decision was made to reinforce political ties with Israel. Germany likewise chose the IRIS-T over the National Advanced Surface-to-Air Missile System, picking a platform produced by a small domestic company over one with similar capabilities but greater interoperability with 13 national operators.

France’s localized approach could enable greater interoperability, benefit a wider swath of European defense industries, and better support European cooperation over the long term. The chief concern, however, is that it would slow down European investments in air and missile defenses until the allies can agree upon a framework for joint development and acquisition. Other European cooperative projects like the Franco-German Future Combat Air System have faced delays due to disputes over the division of labor and technology sharing. Supposing negotiations and planning are successful, Europe would need to greatly expand its production capacity to satisfy regional air defense requirements solely through indigenously produced defenses. Assuming that is possible, it is still not guaranteed that Europe’s combined efforts will produce air and missile defenses that cover the wide spectrum of modern aerial threats.

Maintaining the Federated Status Quo

The third vision maintains the status quo. NATO air and missile defense currently operates under a federated, state-led approach in which the allies research, develop, acquire, and deploy air and missile defenses of their choosing. They can cooperate across these efforts, but national leaders remain the sovereign decisionmakers on all related choices.

A MITRE report aptly describes the state-led vision, saying that “While some past approaches have attempted to address [integrated air and missile defense] by eliminating the diversity and creating a single system that captured all requirements from all nations, a more efficient system is to embrace the existing diversity and aim to federate and integrate across the variety of national systems.” The MITRE report argues that a federated approach can be effective so long as NATO allies can share data to create a common air picture, coordinate their responses to incoming threats, and perform computer simulations to inform their understanding of the threat landscape and identify air defense gaps.

The federated approach is politically simple and stable. Unlike the NATO-designed framework, it is less vulnerable to rising U.S. and European political populism. The United States does not subsidize European air defense as it currently does with ballistic missile defense. The allies do not need to restructure their air defense production lines to satisfy common technical standards, or buy common defenses to fulfill their unique security requirements. The federated approach recognizes the dominance of domestic politics over optimized defense production plans, the brittleness of cooperative development programs, and varied willingness to confront Russia.

Additionally, ad hoc coordination can be made to work, even under stressful conditions and with a wide range of systems. Consider the mishmash of alliances and systems involved in stymying the recent Iranian attack on Israel, in which U.S., U.K., Israeli, French, Jordanian, and other partners jointly defeated Iranian ballistic missiles, cruise missiles, and drones. Or Ukraine’s ability to piece together NATO and Soviet-era systems into an adequate air defense out of necessity. Training and audits can offset some of the technical barriers and allow allies to find and fix gaps in joint operations. To be sure, this approach is suboptimal compared with allies employing integrated or common defenses. But it can work.

The downside with the federated approach is obvious: Cooperation is difficult. Unlike the NATO-designed architecture or European procurement initiatives, there is no agreed upon framework for developing or acquiring common air defense systems. NATO members might also forsake potential cost savings from pre-scheduled bulk buys while production lines are flowing. NATO defense plans and allied interoperability take a back seat to national politics and economic priorities, which enables poor decision-making. Turkey’s acquisition of the Russian S-400, for example, was counterproductive to NATO goals.

Recommendations

The debate over these visions may not be resolved for some time. Yet as NATO considers its options, its window for air and missile defense modernization is time limited. Russia’s air and missile threat is clear, and NATO allies presently have the political resolve and defense budgets available to significantly improve their defenses. The following recommendations are ways that NATO can facilitate coordination among its members today, and thereby support a more robust defensive architecture over the near term.

Publish goals and benchmarks

NATO’s broad goals for air defense should be published, clear, and tractable, and the metrics for evaluating their progress should likewise be open to the public. Leaked reports that NATO only has 5 percent of its required air defenses spread quickly and raise eyebrows, but are generally unhelpful without information on how those requirements were developed. The conflict scenario and campaign plan under consideration remain unknown, as does whether the 5 percent figure refers to the number of interceptor missiles, launchers, or otherwise.

In the tug-of-war between revealing capabilities to deter Russia and concealing them to win a future war, NATO is overcommitting to the latter, and thereby risks Russian President Vladimir Putin underestimating the alliance’s strength and resolve. Its failure to lay out specific benchmarks also makes it difficult to maintain a collective strategy or hold allies accountable. We are left playing the “Who’s paying 2 percent of gross domestic product?” game.

Study and implement lessons from modern warfare

There is more to be learned in this space. The Missile Defense Project at the Center for Strategic and International Studies has published relevant takeaways from the Russian-Ukrainian war and other modern conflicts, as have various other think tanks. Yet there are dozens more lessons that deserve in-depth examination, either directly by NATO or via their sponsorship of studies and conferences. Researchers should be specific in their policy recommendations and, where possible, encourage small-scale investment and experimentation, which might then lead to larger investments and policy change.

Ukraine’s Sky Fortress acoustic sensor system provides a good model for NATO learning. The nearly 10,000 ground-based elevated sensor network exemplifies Kyiv’s low-cost, get-the-job-done approach, and has received wide media attention. Some NATO members are now considering deploying a similarly wide thicket of elevated sensors that can detect aerial threats and direct more sophisticated sensors to look in the right direction. These might be acoustic or electro-optical/infrared — the sensor type is open so long as they are small, cheap, distributed, and effective against Russian aerial threats.

Clarify priorities

NATO should clearly lay out its priorities. Their reports tend to list current and emerging aerial threats and possible mitigation efforts in no particular order of importance. Given overlapping requirements among allies to counter Russian drones and cruise missiles, NATO should increase emphasis on joint development and acquisition for counter-unmanned aerial systems and cruise missile defenses. NATO may continue encouraging joint scientific research on countering hypersonics, but it should deprioritize procurement efforts despite apparent European interest. While U.S. policymakers may choose to procure counter-hypersonic defenses in the near future to mitigate Chinese threats, it does not make sense for Europeans with shallow pockets to join these plans.

These recommendations can improve NATO air and missile defense coordination at the margin. They are simple in theory, but political obstacles will probably delay implementation from weeks to years. NATO’s Chair of the Military Committee and the Integrated Air and Missile Defence Policy Committee should nevertheless lead these efforts. Over the longer term, national political leaders and defense ministers should wrestle with the tensions and tradeoffs over their vision for air and missile defense.

Policymakers may choose to support greater NATO involvement in allied air defense development and deployment plans, which would require significant reforms but offers the most extensive military benefits. They could back European procurement initiatives that enable Europe to satisfy key NATO air defense requirements while also possibly improving the regional defense industrial base. Policymakers might maintain the federated status quo due to its simplicity but seek greater cooperation at the margins. They could also pursue a mixed vision — supporting, for example, NATO technical standards and France’s vision to expand European production and procurement of air defenses. NATO and national political leaders should consider these visions and their respective tradeoffs and, to the extent possible, collectively push in favor of one path for allied air and missile defense.

Shaan Shaikh is a fellow in the International Security Program and the deputy director of the Missile Defense Project at the Center for Strategic and International Studies.

Image: Sgt. Mariah Gonzalez