Trump has walked back promises to let Kyiv build Patriot missiles amid concerns that vital technology could fall into Russian hands

Connor Stringer Chief Washington Correspondent. 

Joe Barnes Diplomatic Editor

Published 10 August 2026 

Donald Trump had made giving Ukraine the secret blueprints to Washington’s most advanced missile sound simple.

“We’re going to give a licence to you to make Patriots,” the US president told Volodymyr Zelensky on the sidelines of the Nato summit in Ankara in July.

Once the Americans had shown the Ukrainians how it was done, Mr Trump suggested its factories could begin building their own missiles “pretty quickly”.

Or at least, that is what he thought.

Mr Trump has since walked back his promise. At a cabinet meeting at Camp David in Maryland last Friday, he said: “It’s a hard thing to give away that kind of technology … People that you give that technology, they can some day turn on you.”

His change of heart came from a growing dispute over whether to hand over the technology, which aides and experts fear could fall into Russian hands, The Telegraph has learnt.

At the heart of Kyiv’s desperation for Patriot missiles is a small radar made by Boeing in Alabama – a part so advanced that the White House restricts its exports even to its closest allies.

Known as the PAC-3 Ka-Band Active Radar Seeker, it serves as the eyes and ears of the interceptor, locating an incoming missile in its final moments of flight and steering the Patriot into a direct collision.

Refusing Ukraine access to this technology could prove existential.

Russia is preparing for another winter campaign of missile and drone strikes against Ukraine’s cities and energy infrastructure while Mr Zelensky’s Patriot stockpiles run dry.

During a Russian bombardment on Wednesday, Ukrainian air defences failed to intercept a single one of the 24 ballistic missiles fired at the Kyiv region. The strike killed 17 people and heavily damaged infrastructure.

“Every anti-ballistic missile package saves the lives of our people. And every night that we lack them results in casualties,” Mr Zelensky said.

The Ukrainian president and generals fear that the winter will be catastrophic.

His chances of securing the 300 missiles needed to protect his nation and survive the rumoured winter onslaught look slim.

The Patriots’ advanced technology

The Patriots’ most advanced part is built by Boeing in a sprawling 63,000 sq ft campus in the city of Huntsville.

A team of engineers assembles the Ka-Band Active Radar, which is housed inside the nose of the missile. The nose is about 10 inches in diameter, with the radar fitting neatly inside at an estimated eight inches wide.

When the missile gets close to its target, the radar generates a high frequency, which allows it to find, lock on to and physically collide with fast-moving ballistic or cruise missiles.

It is so accurate that during the US invasion of Iraq in 2003, Boeing claimed it had not missed a single incoming missile.

While 20 countries buy and operate the Patriot system, the US tightly guards the technical blueprints required to manufacture it and rarely permits foreign manufacturing. Germany and Japan are the only countries that have licences to make their own.

Germany received its licence for Patriot missiles around 2022, as fears developed that Moscow might attack Western Europe. In 2024, Berlin was also granted a contract for a Germany factory to produce its own missiles by next year.

The US granted Tokyo a licence to produce the missile and its components in 2005, when Japanese leaders grew concerned that their own defence systems were no match for North Korea’s missile programme.

However, Washington did not permit Japan to build the highly sensitive Ka-band radar seeker.

It also took Japan’s military three years to test the PAC-3 missile successfully for the first time – a similar timeline analysts expect Ukraine to face.

Glen Howard, the president and chairman of the non-profit The Saratoga Foundation, told The Telegraph: “It could take three years to do this. There is only one facility in Huntsville that produces the component needed.

“The administration gave an emotional endorsement where he wanted to support them, but now they are walking it back.”

Mr Zelensky is desperate for the technology because it is the only air-defence weapon capable of intercepting Russia’s high-speed ballistic and hypersonic missiles.

He returned to the Oval Office in July asking for 300 of the weapons to defend Ukraine from Russia’s winter assault.

Brutally cold weather slows down fighting in Eastern Europe. During cold snaps with Siberian winds, temperatures regularly drop to -20°C.

Russia uses a strategy called “winterisation” to break down Ukraine’s morale by targeting energy grids, plunging cities into darkness and leaving them without heating.

The Ukrainian leader has blamed delays and hesitation from international allies to hand over more Patriot missiles for the deaths of around 16,431 people – including 803 children – who have been killed since the conflict began in 2022, according to the United Nations Human Rights Monitoring Mission in Ukraine.

The Pentagon is also discovering that permission is just the first hurdle in the laborious process to give Kyiv the necessary authorisation for Patriot missiles.

Michael Cadenazzi, the assistant secretary of defence for industrial policy, has said the “hard part” will be finding and certifying an entirely new chain of suppliers.

“There’s only so many engineers that know how to do this stuff. There’s only so many qualified parts [already available],” he said. “As you’re building a new supply chain … it takes time to find the qualified suppliers.”

Preventing Patriots falling into Russian hands

Highly controlled American export law is designed to prevent advanced weapons technology leaving Washington’s control.

Permitting Ukraine to produce its own would require transferring not only the hardware but also the drawings, software and expertise needed to assemble the complex weapon.

A senior UK government source familiar with the American decision-making process said such hurdles were the primary factors for the delay.

Officials would also have to identify every Ukrainian factory, employee and subcontractor who has been granted access to the technology.

Crucially, they would need guarantees that those secrets could not be stolen or given to Russia.

A source close to the US president told The Telegraph that the administration was aware of Ukraine’s history of weapons that had been donated by its allies ending up on Europe’s black market.

Phil Breedlove, a retired four-star general who served as the commander of US European Command and the 17th Supreme Allied Commander Europe of Nato, said: “The story about giving away certain technologies is in fact a concern for the administration.

“I do believe that there is a fear that if we give this technology to Ukraine, that it will somehow make its way to Russia. There are probably voices inside this administration that are worried about the technology getting in Russian hands.”

It is a fear that Mr Trump and his aides seem to share privately. Boeing also shared this concern, with one industry insider saying it was “accurate” that concerns about the weaponry falling into enemy hands were a concern for top officials.

A prime target for Moscow

There is also the issue of where Ukraine would physically assemble the missile. Building it within the country would make it a prime target for Russian strikes.

Two sources familiar with the discussions said as a solution, new interceptors would probably be manufactured in Germany or another European country.

It is an idea understood to be favoured by Elbridge Colby, the United States undersecretary of war for policy.

But experts and insiders say moving production outside Ukraine would take time and further complicate licencing.

Germany, for example, has not finished production at its new Patriot missile factory.

Fabian Hoffmann, a missile expert at the University of Oslo, told The Telegraph: “Both concerns are justified. Agreeing to license production always implies intellectual property risks for the manufacturer that can’t be taken lightly.”

He added: “Patriot facilities would also be a prime target, but everyone is aware of that. So if production were to be relocated, it would have to be moved underground and dispersed. That’s why licensed production would take a long time to establish and be difficult to set up efficiently.”

Boeing, however, remains committed to doing what the administration requires. Industry sources said it had ramped up production of the Ka-Band Active Radar Seeker to a scale that could easily accommodate Ukraine’s demand.

In April, a seven-year framework agreement was reached to triple annual production. Boeing expects to build significantly more seekers as part of this agreement than it built in the previous 26 years combined.

It is also battling renewed domestic demand. The ongoing conflict with Iran is thought to have severely depleted US Patriot interceptor stockpiles.

Some assessments say the military has expended 50 per cent to 65 per cent of its entire Patriot inventory. It is in part, according to reports, why Mr Trump has repeatedly called off planned strikes on Tehran and a return to all-out war.

“Boeing will go along with whatever the government wants it to do. They are focusing on ramping up to meet demands,” one source involved in the licencing discussion said.

Mr Zelensky has made his pitch. But hopes have been crushed by Washington’s eagerness to keep hold of its most sensitive technology.

As another winter of bombardment looms, he must know that time to secure the blueprints and protect his country from an aerial onslaught is running out.

The article is copiously illustrated with photos, diagrams and technical drawings, which I could not upload. Original article here :

https://www.telegraph.co.uk/us/news/2026/08/10/zelensky-patriot-missiles-boeing-eight-inch-radar-system/