During their bilateral meeting on the sidelines of the NATO summit in Ankara, US President Donald Trump and Ukrainian President Volodymyr Zelensky reached a major agreement regarding Patriot Advanced Capability-3 (PAC-3) missile interceptors.
The PAC-3 is the premier hit-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 arrangement 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 US inventory, “to bridge the gap.” Ukraine is confident it can manufacture PAC-3 missiles under license.
Today, the only production of PAC-3 missiles outside the US is in Japan, where Mitsubishi Heavy Industries produces them under license.
The designation “PAC-3 Interceptor” is important. The US is focusing on expanding production of the PAC-3 MSE interceptor missiles, which offer significantly greater range and other improvements over the PAC-3. While it needs clarification, it appears President Trump offered PAC-3 but not PAC-3 MSE to Ukraine.
The US and Ukraine will soon start “technical talks” where many of the major issues, still undecided, can be addressed.
The MSE variant represents a comprehensive redesign optimized to defeat more complex, faster tactical ballistic missiles and hypersonic threats. There are many changes to the MSE. One of them is to go from a single pulse to a dual pulse rocket motor.
The MSE’s motor can ignite its first pulse to clear the launcher and accelerate toward the target area, then coast before igniting a second pulse later in flight. This provides a critical burst of kinetic energy right during the terminal phase, allowing the missile to pull high-G maneuvers against actively evading or high-velocity incoming threats.
It is not clear if the MSE version can defeat Russia’s hypersonic missiles such as the Kinzhal, Zircon or Oreshnik. The PAC-3 version would face problems against the Kinzhal and Zircon and probably not be able to stop the Oreshnik.
The US is struggling to manufacture a significant number of PAC-3 missiles, both standard ones 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 if these procurement targets can be met.
Lockheed Martin is the license holder for the PAC-3 interceptor. However, Lockheed depends on some 400 suppliers including Boeing, which manufactures the all-important sensor package for the missiles and Rocketdyne that makes the rocket engines.
Even when there are no supplier problems, it takes Lockheed two years to manufacture a missile. However, many of the suppliers have fallen way behind in producing critical components, including Boeing and Rocketdyne.
Mitsubishi is a solid aerospace company with lots of defense manufacturing experience including meeting US requirements for defense products. At the present time, Mitsubishi produces around the same rate as Lockheed, but in much lower numbers.
Last year, Mitsubishi delivered 30 PAC-3 MSE interceptors. The company claims it could increase production to 60, but it is prevented from doing so because critical supplies, especially missile 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 raise the probability of a kill (although we do not have reliable kill probabilities against different threats). This means Mitsubishi’s annual production is a drop in the bucket given the multiplicity of threats and the proliferation of enemy missiles, cruise missiles and drones.
There are no hard numbers on the currently remaining number of PAC-3 missiles in the US inventory. The figures are classified, meaning all we have are guesstimates.
The US and its Gulf allies fired a large number of PAC-3 missiles in the war with Iran. On top of that, Ukraine used large numbers of Patriots to fend off Russian missile and drone attacks.
The US inventory size is variously estimated by defense specialists at around 2,000 to 2,500. Even taking into account the US effort to ramp up manufacturing, the build time and supply issues suggest that the US can’t really augment its inventory significantly before 2028 at the earliest, and more likely not until 2030.
If Ukraine starts from scratch with a Lockheed license, and possibly 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 demands and produce enough skilled labor, the output will fall far short of Ukraine’s military requirements.
There is a lot of risk in Ukraine producing PAC-3 interceptors. Risks include Russian penetration of manufacturing know-how and technology, theft of critical components, and exposure to attack from Russian missiles and drones.
Increasingly, Russia is targeting known Ukrainian defense factories, and one would think a PAC-3 production line would be a prime target for the Russians.
There is also a question of who will pay for a Ukrainian factory. The Trump-Zelensky agreement did not cover financial issues, but the US will be requesting NATO countries to foot the bill.
Ukraine has few options for sophisticated air defenses. Europe has some, but in short supply and with their own set of bottlenecks. There also is increasing resistance in Europe to part with critical air defenses, especially because 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 isn’t certain whether South Korea has a system that can perform as well as the Patriot. Another possibility is Israel, but Israel manufactures in partnership with US companies, including Lockheed, Raytheon (RTX Corporation) and Boeing. Israeli supplies are also down because of the recent Iran war.
The US Army is working on a Low Cost Interceptor (LCI) program, which would supplement Patriot and other air defense systems. The project is in a very early stage, but it aims to produce low-cost rocket motors, low-cost seekers, cheaper fire control and guidance software, and easier integration for battlefield use.
LCI could 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 might be a more productive solution for Ukraine, as a four-to six-year time frame for a possible LCI is about the same as trying to produce small numbers of PAC-3 interceptors domestically.
Stephen Bryen is a former US deputy undersecretary of defense and special correspondent at Asia Times. This article was first published on his Weapons and Strategy Substack and is republished with permission.
