NATO’s John Stringer says cheap drones break “shoot everything” air defense doctrine

Sir John Stringer, NATO's Deputy Supreme Allied Commander Europe, says the old Western air-defense playbook is obsolete. The days of “thinking that you can sit back and be reactive and engage every threat that comes at you using traditional means like fast jets and some surface-to-air missiles … those days are over,” Stringer told Business Insider. In his view, modern air threats are multiplying and diversifying so quickly that even the most advanced systems cannot rely on a single strategy: respond to everything with high-cost firepower.

The driver is not just “more drones,” but cheap drones, deployed in large numbers, that stress the economics and the mechanics of defense. Stringer frames the problem as a cost-curve mismatch: Western militaries may still need advanced missiles and aircraft, but they also need “large numbers of cheaper defenses” because there are more threats in the air than ever before. He calls this one of the “biggest changes” facing Western militaries, and he ties it directly to how NATO thinks about control of the skies.

Here is the uncomfortable part: NATO long benefited from total or near-total air control against weaker adversaries, which made its traditional approach feel effective. Stringer points out that the next conflicts may not look like the ones Western forces trained for. Future scenarios could involve major militaries like Russia or China, or could involve smaller actors who can still launch cheap drones in volume, potentially overwhelming defenses built for fewer, more expensive threats. That means the West has to handle the incoming threat “in the reactive sense of stuff coming at us in a different way,” whether that is through new drone types to stop drone attacks or electronic warfare.

If you want the most concrete example of why the “old way” strains under pressure, Stringer points to air defense interceptors. He argues that the “most obvious example of getting that wrong” would be using US-made Patriot air defense missiles against Shahed-style one-way attack drones used by Iran and Russia. Stringer says this is “unsustainable.” He provides the math: Shahed drones are estimated to cost about $20,000 to $50,000 each, while Patriot Advanced Capability-3 (PAC-3) interceptors are estimated to cost roughly $3.7 million each. Patriot stockpiles are strained, and they take a long time to replenish, which turns each intercept into a strategic drain rather than just a tactical action.

This is why alarm bells have already been ringing inside NATO. Business Insider reports officials and military leaders have warned that advanced defenses are still necessary, but they can no longer be the only layer Western militaries rely on. The Ukraine experience is held up as an important proof point: Ukraine has developed solutions including cheap interceptor drones to counter drone attacks instead of using expensive missiles, and partner nations are now following that lead. Stringer also says the West needs cheaper sensors, like the ones Ukraine uses to detect drones, alongside the more powerful systems NATO has been fielding. In other words, it is not just about who can shoot, but who can see early and respond without burning premium resources.

But defense alone is not the finish line. Stringer emphasizes a doctrine shift that many militaries recognize, but that hardens under modern pressure: “your defense needs a good offense.” He argues that the West needs to be able to hit where these weapons are made, the source of an incoming weapon. He uses the analogy of going after “the archer, not just the arrow,” saying that while targeting is often discussed that way, NATO should actually pursue “the places where the arrows are made.” This translates into a broader strategic implication for decision-makers: if your opponents can scale cheap aerial attacks, then your response cannot stop at intercepting; it also has to disrupt production and supply.

That disruption, Stringer argues, requires scaling industrial capacity, not just buying more from traditional defense vendors. He specifically notes Ukraine has demonstrated the value of having more companies ready to adapt for war, including innovative drone companies that were not necessarily part of traditional defense backgrounds five years earlier. He challenges NATO members to think beyond just defense contractors, scaling industrial bases through broader industry readiness. The business parallel is obvious: in a drone-heavy conflict, procurement speed, manufacturing flexibility, and the ability to spin up or retool production can become strategic advantages just as important as platform performance.

Finally, Stringer warns that even with massive investments, the sheer number of threats means Western countries might not be able to protect everything in a serious, large-scale future war. That raises hard choices about what to defend, since adversaries could target military sites, cities, and civilian infrastructure. He also cautions that air threats erode the old assumption that homelands remain safe while forces fight overseas. Missiles and drones can threaten rear areas that previously felt insulated. Stringer says securing air superiority still has to be a priority because it provides the foundation for the joint force’s access and maneuver, but he acknowledges the methods will change. He adds that NATO’s command and control approach will have to adjust too: large command centers used to coordinate and direct air operations are likely to need to become more dispersed to make them harder to target, even if that makes air operations more complicated.

For executives, investors, and operators watching defense and aerospace supply chains, the takeaway is blunt: NATO’s top commander is arguing that success will be measured less by whether you can build the most expensive interceptors and more by whether you can build a layered, scalable ecosystem that matches the threat’s cost and tempo.