Here’s a number that should make every American wince: $4 million. That’s what it costs to fire a single Patriot interceptor missile.

Here’s another: $30,000. That’s an estimated price tag of an Iranian Shahed drone — the kind that Tehran has been lobbing across the Persian Gulf at US bases and allied cities since the start of the war four weeks ago.

In other words, we’re spending at least 100 times more to shoot down each drone than our enemies spend to build one.

And it’s not just the cost that’s a problem — it’s also our production capacity. According to the work of Foreign Policy Research Institute, US and Gulf Patriot batteries fired 943 rounds in the first 96 hours of the fighting, consuming 13% and 16% of existing stocks, respectively. Just replenishing those weapons at current production capacity will require 18 months.

That is no way to fight against Iran, much less against a larger adversary like China or Russia.

Russia, for instance, has dramatically expanded the production of its own version of Shahed drones, the Gerans, in Tatarstan, with a total capacity that is estimated by Ukrainian intelligence at around 1,000 drones per day.

Thankfully, Ukraine offers an answer to the problem.

Because Western supplies of anti-air systems, including Patriots, to Ukraine was never adequate to begin with, a number of Ukrainian companies have developed their low-cost alternatives, tailored to destroy Russian drones.

Priced between $1,000 and $2,500, models such as “Sting” and “Octopus” have proven devastatingly effective.

Last month, 70% of incoming Shaheds over Kyiv were taken out by these cheap interceptors rather than by expensive air defense systems. In the Russian barrage against Ukrainian cities earlier this week, Ukrainians have neutralized a vast majority of incoming drones and missiles.

Ukrainian drone interceptors are often built on 3D-printed frames, guided by thermal sensors and AI, with a human operator in the loop.

And the innovation cycle is relentless — Ukrainian engineers get real-time feedback from the battlefield and iterate in days, not years.

That’s exactly the kind of capability the Pentagon needs but doesn’t have. And despite President Trump’s assurances that America has “the best drones in the world” and needs no help from Ukraine, the reality on the ground tells a different story.

Ukrainian interceptor drones and operators are already being helping US forces and Gulf allies. Kyiv is reportedly in talks with more than 10 countries about drone defense cooperation, including Saudi Arabia and the UAE.

For Ukraine, this is well-earned leverage. A country that has been periodically told to say “thank you” to Washington for military aid is in a position to provide the US military with technology it desperately lacks.

This is not about one or two novel anti-air systems. What lies at heart of the challenge is that the nature of drone warfare is evolving at breakneck speed.

Russia has already improved on the original Shahed design and scaled up its production. Moscow is now rolling out the Geran-5 — a faster, jet-powered variant approaching cruise missile speeds, which makes the current generation of interceptors harder to use.

The Russians are also experimenting with swarm tactics: one lead drone equipped with AI coordinates a group of others toward their targets, potentially overwhelming defenses. Today’s solutions can quickly become tomorrow’s obsolete junk.

In other words, the United States and its allies cannot just buy a bunch of Ukrainian drone interceptors and call it a day. What’s needed is a continuous partnership — helping Ukrainian companies scale up, set up joint ventures with American and European manufacturers, and build production capacity outside of Ukraine.

Vladimir Putin understands that his window for overwhelming Western defenses is limited. The task for Americans and Europeans is to catch up as quickly as possible. Doing so requires an overhaul to the old model of military procurement.

Buying expensive hardware and stockpiling it for years will not help us. Adapting to Russian tactics, and being able to scale up production in time of need is what matters.

In other words, our militaries ought to be buying a stream of constantly changing products and services going into the future — not specific pieces of military kit.

Ukraine internalized these lessons in four years of its struggle for survival, at enormous human and economic cost. Americans and Europeans have a unique, limited opportunity to learn from the Ukrainians, instead of doing it the hard way in face of reckless Russian, Chinese, or Iranian behavior. Let us hope we take it.

Dalibor Rohac is a senior fellow at the American Enterprise Institute in Washington, DC.