US eyes Euro-Japanese next-gen fighter program

A Trump administration envoy’s push for US involvement in a Euro-Japanese fighter jet program has sparked new intrigue, skepticism and strategic questions about transatlantic defense ties.

This month, Defense News reported that Paolo Zampolli, a close associate of US President Donald Trump and US special envoy to Italy, proposed US participation in the Euro-Japanese Global Combat Air Program (GCAP).

As of February 2025, Zampolli, who Trump recently appointed, held meetings with Italian officials, including Deputy Prime Minister Matteo Salvini, to bolster US-Italy defense ties.

In discussions with Italian media and Defense News, Zampolli advocated for a unified transatlantic fighter jet program, claiming it would benefit the US and GCAP members—the UK, Italy and Japan—by reducing costs and improving collaboration.

Zampolli also emphasized its potential to strengthen economic and commercial relations. It was not immediately clear if Zampolli was speaking in his personal capacity or at Trump’s direction.

Italian politicians, including Foreign Minister Antonio Tajani, were surprised at Zampolli’s mission, underscoring the proposal’s nascent stage—US defense contractor Lockheed Martin reserved comments, directing inquiries to relevant governments.

The GCAP’s capabilities could explain how US defense interests align or contrast with this program. In a May 2024 article for the Royal United Services Institute (RUSI), Trevor Taylor and Isabella Antinozzi mention that the GCAP retains significant human-machine integration, similar to the US Next-Generation Air Dominance (NGAD) program.

However, the NGAD program faces an uncertain future, with escalating costs, shifting strategic priorities and the rise of drone warfare casting doubt on its viability.

The US Air Force has paused the NGAD program, reassessing whether the US can maintain air superiority through a combination of existing platforms like the F-35, F-15EX, and F-22 alongside Collaborative Combat Aircraft (CCA).

Cost concerns are paramount, with each NGAD fighter projected to cost USD 250 million per unit. Some officials push for a scaled-down, software-driven light fighter as a cost-effective alternative.

Meanwhile, the US Navy is advancing its F/A-XX program to succeed the F/A-18 Super Hornet and integrate manned-unmanned teaming. However, budget constraints threaten this effort, with US Department of Defense (DOD) officials warning that prioritizing submarine production could render the F/A-XX “unexecutable.”

The US Air Force’s broader airpower readiness is in decline, with the service reporting its lowest mission-capable rates in decades.

The GCAP and NGAD are touted as “sixth-generation” fighters. While there is no consensus on what a sixth-generation fighter is, the type may have optionally-manned capability, manned-unmanned teaming capability and incorporation of new and emerging technologies such as AI, data fusion and advanced communications equipment.

Recent technology developments in the US NGAD program could benefit the GCAP, helping the US and its partners to speed up the development of sixth-generation fighters.

For instance, Air & Space Forces Magazine reported in February 2025 that GE Aerospace and Pratt & Whitney have cleared the US Air Force’s Detailed Design Review for their Next-Generation Adaptive Propulsion (NGAP) engines, marking a critical step toward prototype fabrication.

Air & Space Forces Magazine says GE’s XA102 and Pratt & Whitney’s XA103 engines leverage model-based systems engineering and digital design tools, streamlining development.

The report mentions that while Pratt & Whitney begins hardware procurement for XA103 ground testing in the late 2020s, GE continues refining its digital engine model.

The report says that although engines offer improved fuel efficiency, power management and survivability compared to existing models, the future of NGAP is unclear due to the US Air Force’s evaluation of NGAD’s feasibility. It adds that budget issues and strategic re-evaluations also impact its future.

US support for GCAP may help the latter’s stakeholders prepare for next-gen air power developments from China and Russia.

China’s introduction of the J-36 and J-50 fighters represents a significant advancement in its military aviation capabilities. The J-36, created by Chengdu Aircraft Corporation, showcases a tailless delta wing design with three engines, prioritizing stealth and high-speed performance.

The J-50, from Shenyang Aircraft Corporation, has a twin-engine configuration and stealth technologies, including tailless designs to reduce radar signatures. These aircraft, touted as sixth-generation fighters, reflect China’s ambition to achieve air superiority and challenge US dominance.

As for Russia, Lionel Becher mentions in an April 2024 article for the US Foreign Military Studies Office (FMSO) that Russia is actively pursuing the development of a sixth-generation combat aircraft, aiming for a prototype by 2050.

Becher says the initiative, led by Russia’s State Research Institute of Aviation Systems, involves extensive research and collaboration with military specialists to anticipate future conflict demands.

He states that the planned aircraft integrates advanced digital features, including AI, data fusion, and enhanced command, control and communication capabilities. He notes that despite historical challenges with delays and cost overruns in military aviation, Russia is determined to advance its air combat capabilities.

However, bringing the US into the GCAP program could undermine the latter’s rationale—strategic autonomy regarding defense capabilities for its stakeholders.

In a January 2024 article for the Royal Aeronautical Society, Joe Coles mentions that the UK’s commitment to the program stems from a desire to maintain sovereignty over its defense capabilities.

Coles points out that relying solely on foreign platforms like the US F-35 restricts the UK’s operations, modifications and export autonomy.

He says that while historically international collaborations, such as the SEPECAT Jaguar and Eurofighter Typhoon, have faced challenges including project delays and complex upgrades, they also harness the combined expertise of participating nations.

Discussing Italy’s perspective on GCAP, Lorenzo Cladi and Andrea Locatelli mention in a December 2023 article in the peer-reviewed Contemporary Italian Politics journal that Italy’s decision to join the GCAP fighter program over the Franco-German Future Combat Air System (FCAS) stemmed from a convergence of military, industrial and strategic considerations.

Cladi and Locatelli say that despite Italy’s historical support for EU defense initiatives, Italy prioritized continuity with the UK, a long-standing defense partner, even after Brexit. They note that Italian defense firms, particularly Leonardo, saw more significant technological and economic advantages in GCAP, given its close ties with BAE Systems.

They also add that the Italian Air Force favored GCAP due to extensive operational cooperation with the UK.

Japan’s troubled history with the US regarding fighter aircraft development may have led it to consider alternative partners. In a May 2019 Carnegie Endowment for International Peace (CEIP) article, Gregg Rubenstein says that while the US seeks alignment on operational requirements and alliance security, Japan prioritizes domestic defense industry growth and autonomy over key technologies.

Rubenstein says the US hesitates to share advanced fighter technology without clear strategic benefits. He recalls tensions from the FSX program of the 1980s when trade concerns overshadowed military priorities. He also notes that Japan’s participation in GCAP may raise US concerns about losing influence over Japan’s defense industry.

Given those concerns, bringing the US into GCAP could redefine transatlantic defense collaboration—or hobble the strategic autonomy the program aims to protect.