Could the UK’s Future Nuclear-Capable F-35A Fleet Extend Beyond the Initial 12 Aircraft?

AeroMorning – John Smith – July 15, 2026

The United Kingdom’s decision to acquire 12 Lockheed Martin F-35A Lightning II fighters and join NATO’s Dual-Capable Aircraft (DCA) mission represents one of the most significant developments in British defence and nuclear policy in decades.

A Dual-Capable Aircraft (DCA) is a combat aircraft certified to carry both conventional weapons and US B61-12 nuclear gravity bombs under NATO’s Nuclear Sharing arrangements. The UK’s acquisition of the F-35A will restore an airborne nuclear capability to the Royal Air Force (RAF) for the first time in nearly three decades.

While the UK government has officially confirmed the purchase of an initial batch of 12 aircraft, no final fleet size has yet been announced. The question now being asked by defence analysts is whether those 12 aircraft represent simply the first step toward a larger fleet required to sustain a credible long-term contribution to NATO’s nuclear deterrence mission.

The UK’s return to an airborne nuclear role

The announcement marks the return of an airborne nuclear capability to the RAF for the first time since the retirement of the WE.177 free-fall nuclear bomb in 1998.

Following the withdrawal of the WE.177, the United Kingdom became the only recognised nuclear weapon state whose nuclear deterrent relied exclusively on a single delivery system: the Royal Navy’s Trident ballistic missile submarines.

The introduction of the F-35A does not create a second independent British nuclear force. Instead, it restores an air-delivered nuclear capability through NATO’s Nuclear Sharing arrangements using US-owned nuclear weapons.

F-35A and F-35B: Two Different Roles

Although externally similar, the F-35A and F-35B are designed for different missions.

The F-35A therefore provides capabilities that complement rather than replace the UK’s existing fleet of F-35Bs.

The aircraft will become a Dual-Capable Aircraft (DCA).

A complementary nuclear posture

The UK’s future nuclear posture would combine two fundamentally different systems.

This distinction is fundamental.

The F-35A mission would rely on US-owned nuclear weapons, US custody of those weapons, and US authorisation for their release, while the United Kingdom’s sovereign nuclear deterrent would remain entirely submarine-based and under exclusive British political control.

Why join NATO’s nuclear-sharing mission when the UK already possesses Trident?

Although the United Kingdom already maintains an independent strategic nuclear deterrent, the two capabilities fulfil fundamentally different military and political roles.

The Trident force provides the UK’s ultimate strategic deterrent, designed to respond to existential threats against the nation.

An airborne nuclear capability offers different advantages:

• a visible and deployable deterrent during periods of tension;
• a flexible theatre-level nuclear response;
• stronger integration within NATO’s collective deterrence posture;
• additional response options between conventional military operations and strategic nuclear retaliation.

Rather than replacing Trident, the F-35A complements it by providing an additional level within the Alliance’s deterrence spectrum.

How NATO Nuclear Sharing works

Under NATO’s Nuclear Sharing arrangements:

• the United States retains ownership of the nuclear weapons;
• the United States maintains custody of the weapons during peacetime;
• participating allies provide certified aircraft, trained aircrews and supporting infrastructure;
• allied crews train regularly for the nuclear mission under NATO procedures;
• in the event of a major crisis or conflict, any release of nuclear weapons would require a political decision within NATO together with authorisation by the President of the United States.

The F-35A aircraft would therefore be capable of delivering US B61-12 nuclear gravity bombs, not British nuclear weapons.

NATO countries participating in the Dual-Capable Aircraft mission

European NATO members currently participating, or committed to participating, in the Alliance’s nuclear-sharing mission include:

• Belgium;
• Germany;
• Italy;
• Netherlands;
• Türkiye;
• the United Kingdom (following the introduction of the F-35A).

These nations provide certified aircraft, trained crews and supporting infrastructure as part of NATO’s collective nuclear deterrence posture.

Why 12 aircraft may represent only the beginning

Although the government has announced the purchase of 12 F-35As, sustaining a credible and enduring contribution to NATO’s nuclear deterrence mission requires considerably more than simply acquiring 12 aircraft.

Any modern combat aircraft fleet must account for:

• scheduled maintenance;
• depot-level inspections;
• pilot conversion and recurrent training;
• operational work-up;
• aircraft upgrades;
• reserve capacity;
• deployment requirements.

Consequently, only a proportion of any fighter fleet is available for operational missions at any given time.

This is why defence planners typically evaluate fleet size not simply on the basis of the number of aircraft required for operations, but also on the overall force needed to sustain readiness over many years.

Building a capability—not simply buying aircraft

Establishing a NATO Dual-Capable Aircraft capability involves much more than acquiring fighter aircraft.

It also requires:

• specialised pilot and ground crew training;
• certification for nuclear operations;
• secure storage and handling infrastructure;
• integration into NATO nuclear planning;
• regular multinational exercises;
• dedicated maintenance, logistics and security procedures.

The aircraft themselves represent only one element of a much broader operational capability.

Could the RAF eventually require more F-35As?

The United Kingdom has previously stated its long-term ambition to acquire up to 138 F-35 aircraft over the life of the programme.

Future procurement decisions are expected to balance:

• F-35B aircraft for carrier operations;
• F-35A aircraft for land-based conventional missions and NATO’s nuclear-sharing role.

No official decision has yet been announced regarding the ultimate number of F-35As that the RAF may eventually operate.

However, maintaining an enduring nuclear capability requires balancing operational availability, training, maintenance, infrastructure and NATO commitments. These considerations are likely to play an important role in determining future procurement decisions beyond the initial batch of 12 aircraft.

Conclusion

The acquisition of the F-35A represents the United Kingdom’s return to an airborne nuclear role after nearly three decades, but not the return of an independent airborne nuclear force.

Instead, the RAF will contribute to NATO’s Dual-Capable Aircraft mission using US-owned B61-12 nuclear gravity bombs, while the United Kingdom’s sovereign nuclear deterrent will remain exclusively based on the Royal Navy’s Trident submarine force.

Whether the initial order of 12 aircraft ultimately evolves into a larger F-35A fleet will depend on future UK defence planning, NATO force requirements, available funding, industrial considerations and the operational experience gained after the aircraft enter service.

What is already clear, however, is that the introduction of the F-35A marks a significant evolution in the UK’s contribution to NATO’s nuclear deterrence posture, restoring an airborne nuclear capability that has been absent from the Royal Air Force since 1998 while preserving the UK’s independent strategic deterrent at sea.