During their bilateral meeting on the sidelines of the NATO summit in Ankara, US President Donald Trump and Ukraine’s Volodymyr Zelensky reached a major agreement regarding Patriot Advanced Capability-3 (PAC-3) missile interceptors.
The PAC-3 is the primary strike-to-kill air defense missile used by the US and many of its allies. The weapon has played a major role in the Iran conflict.
The proposed deal for Ukraine has two parts: a political agreement to give Ukraine a license to manufacture PAC-3 interceptors; and a short-term supply of PAC-3 interceptors from the US inventory, “to bridge the gap”. Ukraine is confident that it can produce PAC-3 missiles under license.
Today, the only production of PAC-3 missiles outside the US is in Japan, where Mitsubishi Heavy Industries manufactures them under license.
The designation “PAC-3 Interceptor” is significant. The US is focusing on expanding production of the PAC-3 MSE interceptor missiles, which offer much greater range and other improvements over the PAC-3. While it needs clarification, it appears that President Trump offered Ukraine the PAC-3, but not the PAC-3 MSE.
The US and Ukraine will soon begin “technical talks” where many of the key issues, still undecided, could be addressed.
The MSE variant represents a comprehensive redesign optimized to defeat more complex, faster tactical ballistic missiles and hypersonic threats. There are many variations in MSE. One of them is the transition from a single pulse to a double pulse rocket motor.
The MSE engine can fire its first pulse to clear the launcher and accelerate to the target area, then coast before firing a second pulse later in flight. This provides a critical burst of kinetic energy right during the terminal phase, allowing the missile to pull off high-G maneuvers against incoming threats actively or at high speed.
It is not clear whether the MSE version can defeat Russia’s hypersonic missiles such as the Kinzhal, Zircon or Oreshnik. The PAC-3 version would face problems against Kinzhal and Zircon and probably wouldn’t be able to stop Oreshnik.
The US is struggling to produce significant numbers of PAC-3 missiles, both standard and MSE versions. The US Army requested an unprecedented 2,798 PAC-3 MSE interceptors, and the Navy requested an additional 405 modified variants for AEGIS ships, both part of the FY 2027 Budget Request. There are serious questions about whether these procurement targets can be met.
Lockheed Martin is the license holder for the PAC-3 interceptor. However, Lockheed depends on about 400 suppliers, including Boeing, which makes the sensor package critical to the rockets, and Rocketdyne, which makes the rocket engines.
Even when there are no problems with suppliers, it takes Lockheed two years to produce a missile. However, many of the suppliers have fallen far behind in the production of critical components, including Boeing and Rocketdyne.
Mitsubishi is a solid aerospace company with a lot of experience in defense manufacturing, including meeting US requirements for defense products. At the present time, Mitsubishi produces about the same rate as Lockheed, but in much lower numbers.
Last year, Mitsubishi delivered 30 PAC-3 MSE interceptors. The company claims it can ramp up production to 60, but is constrained from doing so because critical supplies, particularly rocket seekers from Boeing, are in short supply.
The US has asked Mitsubishi to increase production to 100 missiles, assuming supply chain problems are resolved and if Mitsubishi can increase its staff and production capacity.
Keep in mind that typically two PAC-3 interceptors are fired at each target to increase the probability of a kill (although we don’t have reliable kill probabilities against different threats). That means Mitsubishi’s annual output is a drop in the bucket, given the variety of threats and the proliferation of enemy missiles, cruise missiles and drones.
There are no hard numbers on the number of PAC-3 missiles currently remaining in the US inventory. The numbers are classified, which means all we have are guesses.
The US and its Gulf allies launched a large number of PAC-3 missiles in the war with Iran. Additionally, Ukraine used large numbers of Patriots to fend off Russian missile and drone attacks.
The size of the US inventory is variously estimated by defense specialists at around 2,000 to 2,500. Even taking into account US efforts to increase production, the timing and supply issues suggest that the US cannot realistically increase its inventory significantly before 2028 at the earliest, and most likely not until 2030.
If Ukraine starts over with a Lockheed license, and is perhaps given some priority in the supply chain (which is not a sure thing), Ukraine can only hope to produce PAC-3 interceptors starting in 2029 to 2030.
If the scale is similar to Mitsubishi and Ukraine can manage the technology requirements and produce enough skilled labor, production will be far below Ukraine’s military requirements.
There is too much risk in Ukraine to produce PAC-3 interceptors. Risks include Russian penetration of manufacturing know-how and technology, theft of critical components, and exposure to attacks by Russian missiles and drones.
Increasingly, Russia is targeting known Ukrainian defense factories, and one would think that a PAC-3 production line would be a prime target for the Russians.
There is also the question of who will pay for a Ukrainian factory. The Trump-Zelensky deal did not cover financial matters, but the US will ask NATO countries to foot the bill.
Ukraine has few options for sophisticated air defense. Europe has some, but in short supply and with its own narrow packages. There is also growing resistance in Europe to part with critical air defenses, particularly as the US has little of its own to spare and is pulling back from its NATO defense responsibilities.
Other possible sources include South Korea, but it is uncertain whether South Korea has a system that can perform as well as the Patriot. Another option is Israel, but Israel manufactures in partnership with American companies, including Lockheed, Raytheon (RTX Corporation), and Boeing. Israeli supplies are also down due to the recent war in Iran.
The US military is working on a low-cost interceptor (LCI) program, which would complement the Patriot and other air defense systems. The project is at a very early stage, but aims to produce low-cost rocket motors, low-cost seekers, cheaper fire control and guidance software, and easier integration for battlefield use.
LCI can be very attractive for Ukraine. Kyiv is well-positioned to participate if the US allows foreign companies to participate in the program, which is essential to its success.
It may be a more productive solution for Ukraine, as a four to six year time frame for a potential LCI is about the same as trying to produce a small number of PAC-3 interceptors domestically.
Stephen Bryen is a former US deputy secretary of defense and special correspondent at the Asia Times. it ITEM was first published in his Weapons and Strategy Substack and reprinted with permission.
