Sovereignty for Sale? Why Britain Must Rebuild Its Own Combat Air Power
News and information from the Advent IM team.
- by Olivia Lawlor-Blackburn
- Advent IM Blog
Between Q1 2019 and Q4 2024, the Ministry of Defence (including its arms length bodies) paid roughly £52.5 billion to private sector contractors—about half to UK headquartered firms and much of the remainder to U.S. companies like Boeing and Lockheed Martin. Tussell’s analysis shows a clear pattern: the lion’s share of non UK spend goes to U.S. suppliers, with the U.S. DoD invoicing the UK £700 million since 2022 for programmes including the F 35 .
This reliance comes at a time when Britain’s own aerospace manufacturing base is under pressure—factory closures, skills erosion, and a proud legacy of innovation giving way to dependency. Every pound spent overseas is a pound not invested in rebuilding sovereign capability at home. And yet the MOD’s own statistics remind us how pivotal domestic industry remains: 84% of global MOD expenditure with industry in 2023/24 took place in the UK, even counting work delivered via U.S. Foreign Military Sales when the work is performed here. The picture is nuanced—but our highest end platforms still tie us to U.S. decisions and supply chains .
When I look at Europe’s defence posture today, one trend stands out: an increasing dependence on American hardware. The UK is no exception. Our flagship fighter programme—the F 35 Lightning II—is the prime example. As of March 2025, the MOD reported £9.35 billion spent on F 35 equipment and support, while the National Audit Office (NAO) assessed the whole life cost at £71 billion once personnel, fuel, infrastructure and other costs are included . That is a far cry from early business case assumptions—and a reminder that strategic dependence carries a real price tag.
The F 35 isn’t just a jet; it’s a complex ecosystem of software, parts, mission data systems and global logistics largely controlled across the Atlantic. If Washington changes export rules, priorities or software release schedules, our ability to deploy could be curtailed overnight. The GAO’s 2025 report laid bare how TR 3 hardware/software delays pushed average delivery slippages to 238 days in 2024—a U.S. bottleneck instantly felt by allied air forces .
These aren’t abstract programme charts; they are operational gaps. Denmark and Belgium both reported uncertainty over delivery schedules as TR 3 slowed hand overs, complicating pilot training and fleet transition plans. The ripple effects are obvious: older aircraft fly longer, availability and capability dip, and budgets (already strained) pay for interim fixes. It’s a textbook example of how U.S. production and certification problems flow straight into European defence timelines. And we are not immune; our own F 35 force rides the same wave .
If the U.S. were to restrict access to critical components, mission data, software or depot level maintenance—not just for the F 35 but across the spectrum of U.S. made systems—the impact on UK defence would be profound. Airpower, missile defence, ISR platforms and elements of cyber capability are all interwoven with U.S. export controls and vendor ecosystems. A sudden policy shift could stall operations, ground aircraft and disrupt integrated systems that underpin NATO missions. GOV.UK data shows we remain active users of Foreign Military Sales (e.g., £614 million via FMS in 2023/24), reinforcing the practical reality that some critical capabilities are procured on U.S. terms .
This vulnerability matters because we operate in a high threat environment. We are a leading supporter of Ukraine, and our deterrence posture at home is under increasing strain. Russian submarines and surveillance vessels have been probing UK waters and mapping undersea cables, triggering joint UK Norway counter measures and new Atlantic Bastion investments in autonomous maritime ISR. If our frontline assets or data chains were degraded during a U.S. policy hiccup or vendor outage, we would struggle to reinforce NATO’s eastern flank and to police our own seas.
If a cyberattack can halt Jaguar Land Rover’s production, imagine the chaos if a major defence prime or critical sub tier supplier suffered an equivalent IT meltdown. Defence supply chains are sprawling, global, and software heavy; a single disruption can cascade across fleets, grounding aircraft and delaying missile systems. We’ve seen it play out: the Interlock ransomware attacks on AMTEC/National Defense Corporation disrupted ammunition manufacture and leaked sensitive logistics data referencing top defence contractors—blueprints an adversary could use to intercept or sabotage deliveries . The Stark Aerospace incident allegedly exposed terabytes of design files, firmware and supply chain details. This is the defence industrial base under cyber siege.
And state linked espionage isn’t theoretical either: in 2025, APT41 campaigns targeted operational technology networks across aerospace and aviation supply chains—precisely the mid tier firms that keep high end platforms ticking. You don’t need to compromise a marquee OEM to break an air force; you only need to knock over the right supplier at the right time.
This raises a bigger question I can’t ignore: why isn’t the UK—the birthplace of icons like the Spitfire and the Harrier Jump Jet—designing and building its own next generation aircraft? Have we accepted that our future lies in dependency rather than innovation?
The truth is, we are trying—but our intent needs resourcing and urgency. The trilateral Global Combat Air Programme (GCAP) with Japan and Italy has moved from MoUs to a joint venture prime—headquartered in Britain—aiming for service entry in 2035. That JV (now operational as Edgewing) will act as the design authority and subcontract manufacturing to BAE Systems, Leonardo and Mitsubishi, anchoring skilled jobs and sovereign design in the UK for decades. If we want to reclaim genuine sovereignty, GCAP must be funded, accelerated and protected from the stop start budgeting that has plagued past programmes.
Dependency on foreign controlled systems makes our sovereignty conditional. When the UK cannot guarantee the availability of its own defence tools, we risk being unable to act decisively—whether that’s protecting our waters, supporting allies, or responding to a crisis on our own soil. The NAO’s findings on F 35 costs and capability gaps are a warning, not a verdict: we can either remain rule takers in someone else’s industrial ecosystem, or build the capability to set our own course .
So here’s my call to action:
• Back GCAP at pace—with stable multi year investment, iron clad delivery governance, and a skills pipeline that grows British design authority.
• Harden the defence supply chain—mandate cyber resilience for primes and sub tiers, diversify sources, and on shore critical components where possible.
• Invest in maritime protection—scale Atlantic Bastion and UK Norway patrol integration to secure undersea cables and infrastructure that our economy and defence depend on.
Sovereign capability isn’t nostalgic—it’s pragmatic. If Britain wants to lead, Britain must build. And if we’re serious about defending our interests—from the Baltic to the North Sea to the Atlantic seabed—we must put our money, our skills and our political will back into British hands.
Mike Gillespie, CEO, Advent IM