Yes, US nuclear weapons have returned to RAF Lakenheath
And the UK's return to the nuclear delivery mission
Note that this article is not yet complete - I’m still working on the US F-35A basing and the UK decision to purchase 12xF-35As. Updates to come.
US nuclear weapons return to the UK→UK rejoins the nuclear mission→NATO gets more deterrence options
From 15-18 July 2025, the United States moved an unknown number of B61-12 air-dropped nuclear bombs from the United States to the United Kingdom: the first placement of US nuclear weapons in the UK since they were removed in 2008. This move was performed in a stunningly transparent manner - below the transparency level of a press briefing, but with every moving piece in plane (ha, sorry, plain) view - which means that the US wanted allies and adversaries alike to take note.
US B61-12s arrived at Royal Air Force Base Lakenheath from Kirtland AFB to supply the USAF 48th Fighter Wing with its own nuclear weapons - and likely to supply the Royal Air Force’s F-35As. In this story, I will do four things:
First, I will go through the evidence of the movement
Second, I will give details on the US aircraft upgrades at Lakenheath
Third, I will describe the return of the nuclear Dual-Capable Aircraft mission to the RAF
And fourth, how this all ties together at NATO
Night (and day) moves
The three Ps: Preparation preparation preparation
10-11 June 2025: RAF Lakenheath prepares for a changed force posture with a security and movement exercise and spot checks.
Here’s the flight details from 15-18 July 2025, all fully transpondered:
15 July 2025 1419Z: C-17A Globemaster [Transponder Reach/RCH4574, Hex #AE2FAC, Registration 08-8200, Type L4J, Squawk 6677] from the 4th Airlift Squadron of the 62nd Airlift Wing took off from Joint Base Lewis-McChord bound for Kirtland Air Force Base as part of Mission PAM112271196.
16 July 2025 1638Z: C-17A [RCH4574 08-8200] lands at Kirtland AB and moves to Hot Cargo Pad 5, with a NOTAM issued blocking overflights from 1952-0152Z: AVOID OVERFLYING AIRCRAFT ON PAD 5 SE OF RWY 8.
17 July 2025 0134Z: C-17A [RCH4574 08-8200 Squawk 0710] takes off, radioing tower: “REACH 4574, haz cargo, ready to taxi” (audio from NukeWatchUK) on takeoff and meets two KC-46 Pegasuses [FLAM11 #AE5BBE Tail 16-46013 Type L2J Squawk 3570 and FLAM12 #AE63C8 21-46092 L2J 2661] (FLAM11 is from the 157th Air Refueling Wing based at Pease Air National Guard Base and FLAM12 is from the 108th out of Joint Base McGuire–Dix–Lakehurst) to refuel over Newfoundland en route to Lakenheath AFB on Missions 8PZ11241S198 and 8PZ11242S198.
17 July 2025 1150Z: C-17A [RCH4574 08-8200 Squawk 0425] lands at RAF Lakenheath, with a NOTAM restricting overflights of the Lakenheath Air Traffic Zone for 17-18 July below 2,000 feet with an added NOTAM restricting all traffic to pre-approved missions only, shutting other landing strips.
17 July 2025 1200Z: C-17A [RCH4574 08-8200] taxis to “Victor Upper Ramp” for offloading onto an MHU-83E Aircraft Aerial Munition Mover to one of the aircraft shelters containing an upgraded WS3 B61 storage vault.
18 July 2025 1522Z: C-17A [RCH4574 08-8200] departs RAF Lakenheath for McChord AFB (not Kirtland, which would indicate it was brining something back, like it did back in April 2025, swapping out B61-6 or -7s for the new B61-12).
19 July 2025 0048Z: C-17A [RCH4574 08-8200] lands at McChord AFB.
Note that a ground spare was sent to Ramstein AFB in case RCH4574 broke down. C-17A [RCH 4205 Reg 09-9211] flew from McChord to Lakenheath 15-16 July, then to Ramstein AB on 16 July, departing Lakenheath for McChord on 17 July and landing on the 18th.
Here’s the second flight, 22-25 July 2025, also fully transpondered:
22 July 1445Z: C-17A Globemaster [Transponder Reach/RCH4574, Hex #AE2FAC, Registration 08-8200, Type L4J] departs McChord AFB for Kirtland on Mission PAM11274203.
22 July 1638Z: C-17A RCH4574 lands at Kirtland AFB, taxis to Hot Cargo Pad 5. Pad 5 is active for more than 4 hours, with a NOTAM issued to avoid overflights from 1752Z-2152Z.
23 July 2248Z: C-17A RCH4574 departs Kirtland AFB for RAF Lakenheath.
24 July 0908Z: C-17A RCH4574 lands at RAF Lakenheath.
25 July 1239Z: C-17A RCH4574 departs RAF Lakenheath for McChord AFB.
25 July 2254Z: C-17A RCH4574 lands at McChord AFB.
The spare for this mission was RCH4134 #AE49C7 09-9211 L4J 2257 (McChord-Lakenheath-Ramstein-McChord) on Mission PAM112475203, with refuelers ADLAY 21 21-46091 (McGuire) and ADLAY22 16-46013 (Pease) on Missions 8PZ11222S205 and 8PZ11221S205.
And, just in case you didn’t get that this was a nuclear airlift:
28 July 2025: Chief Master Sergeant of the Air Force (CMSAF) visits RAF Lakenheath in what is either the greatest coincidence in history or a follow-up visit to the nuclear weapons delivery following his visit to KUMMSC (see below). Note they’re helpfully standing in front of the nuclear weapons storage vault (the red box on the floor).
Here’s the red box extended for loading, offloading, inspections, etc.
What is the evidence that this was a nuclear airlift?
1. Why does it matter that the the 4th Sqdrn, 62nd Wing flew a C-17A from McChord to Kirtland AFB?
The C-17A is certified for nuclear transport and the USAF nuclear airlift mission is owned by the 62nd Wing, and flown by the 4th Sqdrn.
First, the C-17A is certified for the movement of nuclear weapons, including the B61 variants 3, 4, 7, 11, 12, and 13. C-17A can carry about 30 B61s, apparently.
Second, the 62nd Airlift Wing is the only part of the USAF that is certified for the nuclear airlift mission - assigned as the Prime Nuclear Airlift Force (PNAF). The 4th Squadron in particular is the specialist in moving nukes. Here’s a Cold War history of the PNAF mission (including accidents), and here’s PNAF from the Nuclear Security Summit gift-basket.
Here’s a closeup of those 4th Sq shoulder patches:
Why does it matter that the 4th Sqdrn C-17A landed at Kirtland?
Kirtland Air Base is home to the Kirtland Underground Munitions and Maintenance Storage Complex (KUMMSC), a massive nuclear weapons storage facility
The main depository for US B61s is KUMMSC, activated in 1992, with more than 300,000 square feet of storage for nuclear weapons, containing around 2,500 weapons (including other warheads than the B61). It is owned by the US Air Force Nuclear Weapons Center.
The 898th Munitions Squadron (898 MUNS) is in charge of all nuclear weapons storage, safety, movement, loading, and offloading at Kirtland, with the 377th Security Forces Squadron/Weapon Systems Security Squadron (WSSS) providing muscle. The 898th is thus in charge of Special Assignment Airlift Missions (SAAM). Look inside and here!
As stated in the timeline, CMSAF followed up his August 2024 visit to KUMMSC with a visit to the hardened aircraft WS3 shelters at RAF Lakenheath after the two airlifts on 28 July 2025. Conicidence? No. The Air Force does not do coincidence.
What is Hot Cargo Pad 5 and why does it matter that the C-17A loitered there for several hours?
Kirtland AB Hot Cargo Pad 5 is used for nuclear weapons loading from KUMMSC.
Hot Cargo Pad 5 is the designated are for loading and off-loading nuclear nuclear weapons from KUMMSC. It has pre-built guard and firing positions for the 377th and is exerised regularly in case of an assault on the base during loading operations. All loading and unloading operations at HCP-5 require NOTAMs to be issued to prevent overflight.
Why does it matter that the Lakenheath personnel used an MHU-83E?
The MHU-83D and E Aircraft Aerial Munition Movers are certified for moving nuclear weapons.
The safety rules for DCA are detailed here.
Why does it matter that it was RAF Lakenheath?
Lakenheath was a US nuclear weapons base from 1955-2007, with 33 nuclear weapon vaults.
Lakenheath has been a major storage site for US nuclear weapons since they were first introduced into the UK in 1955. Previous nuclear storage was above-ground, leading to a study to build underground storage system, called the Weapon Storage and Security System (WS3).
The WS3 is a system including a nuclear storage vault built into the floor of a hardened aircraft shelter, capable of storing 4 B61s or cruise missile warheads. NATO approved the concept in 1990 built them through common NATO funds at select US bases in Europe. See this article for a more detailed description.
Lakenheath has 33 WS3 vaults total which were mothballed when the US withdrew its nuclear weapons from the UK during the Bush Administration around 2007-2008. The US also built WS3 vaults at RAF Marham before the UK so rudely left the nuclear mission…
In 2021, the decision was taken to restore some of the WS3 vaults at RAF Lakenheath. The FY2021 budget request included trailers to support the surety mission, with the contract let on 17 July 2022 under countract FA942222C0004. The initial completion was on 15 July 2025, with additional work completed on 31 March 2026. Total funding for upgrades was $385 million in the April 2022 DoD Budget.
Personnel training at Lakenheath began in 2023, with guard force dorms built from June 2022-August 2024. Contracting for hardening to protect NATO nuclear command and control against electro magnetic pulses also began in June 2026, with delivery locations including Aviano AB, Italy, Incirlik AB, Turkey, RAF Lakenheath, England, Kleine Brogel, Belgium, Buechel, Germany, Volkel, Netherlands, and Ghedi, Italy. Not sure why they chose that order, tho.
Does have to do with the US F-35As at RAF Lakenheath?
Yes, one of the primary customers for the WS3 vaults at Lakenheath will be the US fighter craft - the F-15Es and F-35As - based there.
o RAF Lakenheath, historic British Air Base, shared with the US from WW2 on until the end of the war, then moved to France, became a permanent US base 15 January 1960 (after getting kicked out of France.
o Had US nuclear weapons from 1954-ish to 2007-ish, including GLCMs Lakenheath received nuclear bombs in 1954-1955, with as of Jun 1958, Mk-6 and Mk-7 Mod 5 (B52s). Removed some time around January 2007 (https://www.theguardian.com/world/2008/jun/26/usforeignpolicy.nuclear)
o US nuclear weapons formerly at Lakenheath and Marham (2007), and Brentwaters and Upper Heyford (1994); with missiles at Greenham Common (1991) and Molesworth (1988)
o US 48th Fighter Wing, the Liberty Wing, 7,000 active duty personnel, and civilians, 11,000 family members, largest US fighter wing in Europe, 4 squadrons of F-15Es (F-15Es after Desert Storm/in 1992) and F-35As (December 2021)
o 492nd 494th Fighter Squadrons – F15Es
o 493rd, 495th Fighter Squadrons – F35As, activated 9 June 2023,
o January 2015: US F-35s to be based in England
o August 2018: Infrastructure improvements begin at RAF Lakenheath ($150 million)
o Lakenheath infrastructure for F35As began in August 2018, announced January 2015 in a speech by Donald Trump.
Does this have anything to do with the UK announced purchase of F-35As?
Yes, the UK has rejoined the nuclear mission by making this purhcase, forcing the RAF to hire nuclear targeters. Currently, among the Services, only the Royal Navy employs staff dedicated to nuclear missions.
· F-35 Article (https://www.f35.com/f35/global-enterprise/united-kingdom.html)
o In 2024, UK reaffirmed 138 F-135Bs, first arrived at RAF Marham June 2018 at 617 Sqn Dambusters; 207 Sqn in 2019, 908 Naval Air Sqn Immortals Marham Dec 2023
o 35th F35B arrives March 2024; F-35Bs from Immortals participated in STEADFAST DEFENDER March 2024
o The SSA would not be used - WS3 vaults in HASs would be used - refurbishment / recommissioning would be required if at Marham or perhaps a deal to use spare capacity at Lakenheath.
o There would be no need to recreate the RAF Armament Support Unit (RAFASUPU) for courses or the Weapons Standardization Team - use the same aircrew and groundcrew training / certification system as other existing NATO Nuclear Sharing partners.
o Competence of the unit in the Dual Capable Aircraft (DCA) role would be evaluated periodically by the NATO TACEVAL Team as is the case for other DCA units at present.
o It would even be possible to play a Nuclear Agile Combat Employment shell game by deploying to other DCA bases in the NATO Region which have WS3 and a MUNSS.
The UK has changed their F35 purchase to prioritize a tranche of F35As, designed to deliver the B61. They will fly in from their home base at RAF Marham.
RAF Lakenheath F-35A aircraft shelter, including the WS3 Weapon Storage Vault on the diagram.
The US B61-12s also will be available for loading on the UK F35As, once delivered, based at RAF Marham, as part of bilateral missions or NATO missions. It will be interesting to see when the UK begins rehearsing this move, as well as integrating such a move into STEADFAST NOON.
F-35As
https://www.lakenheath.af.mil/News/Article-Display/Article/3004447/48th-fighter-wing-welcomes-new-flagships/
https://www.lakenheath.af.mil/News/Article-Display/Article/2503538/us-air-force-names-first-overseas-based-f-35a-squadron/
493rd and 495th Fighter Generation Squadrons under the 48th Fighter Wing
Here’s the must-have coin for the specific USAF unit that will deliver the B61-12 bombs - the 493rd Fighter Squadron of the 48th Fighter Wing, based at RAF Lakenheath.
Starmer said he’s not changing the total number of F35s but buying 12 cheaper F35As v F35Bs.
[Guardian Article 25 June https://www.theguardian.com/world/2025/jun/25/how-and-why-is-britain-obtaining-access-to-nuclear-gravity-bombs-f-35a?CMP=Share_iOSApp_Other]
· F-35As, RAF Marham in Norfolk
· Marham former WE177 storage
· WE177s eliminated in 1998
· US B61s left Lakenheath in 2008
· B-61-12 yields 0.3, 1.5, 10, 50kt
· 12x F-35As out of 138 F-35Bs total ordered
F-35A is cheaper than F-35B
So there’s a savings already in the tens of millions of pounds. And the US already has paid to upgrade Lakenheath’s nuclear storage to hold north of 100 bombs - so there may not be need for refurbishing the old WS3 bunkers at RAF Marham. New option, relatively fast and cheap.
Marham US nuclear WS3 storage eliminated in 1999?
There would be a small additional manning burden in engineering manpower to create a cell on each unit (2 x SNCOs) whose almost full-time job it would be to check that every work order carried out on the aircraft either did not impact the Special Weapons System (SWS) or if it did that the relevant checks had subsequently be carried out. There would also be a need for period SWS certification on each aircraft. This was everyday bread and butter on a Tornado GR1 sqn in the DCA role in the WE177 era.
F-35A has a longer combat radius than F-16C previously used by NATO Nuclear Sharing partners - 590 nm on internal fuel and there would be no shortage of boom equipped tankers for NATO nuclear missions - including NATO MMU with 12 x A330 MRTT (recently increased from 8).
Logistically, RAF Lakenheath would make more sense as the B61-12 storage & loading location and be a lot cheaper. There is more than sufficient vault capacity - 33 x WS3 originally capable of taking 4 weapons each - OSINT indicates 28 x WS3 are being recommissioned currently and new domestic accommodation is being funded for a MUNSS.
Procurement of F-35A for the RAF opens up possibilities for a wide variety of conventional weapons. An RAF wg cdr at Nellis AFB has recently moved up into the Deputy Director of the United Operational Test Team for F-35.
DCA aircraft are not held back from conventional missions for fear of losing them and then not being available for nuclear strike missions - SACEUR prioritizes nuclear missions and units to fill the lines they are still capable of. There is nothing new about this. Many a time as a Tornado GR1 SEngO when 2 x sqns were contributing to a 16-ship airfield attack mission I would wonder how many aircraft would be left for R-Hour. We just did the best we could with an aircraft asset constrained RAF in the same way that the current NATO Nuclear Sharing partners do with an open source estimated allocation of 15 weapons each today.
Very interesting piece - thanks.
I have two 'newbie' questions:
- what are the approx dimensions of a B61-12?
- while the U.S. states that their nukes are 'thermonuclear', they also inform that the quantity of tritium is in the range of 10 grams. The latter claim would suggest that U.S. nukes are 'tritium-boosted' fission bombs. Which is the correct definition?
I'm glad to a subscriber!