Introduction

The US military has had a long association with the UK, retaining a range of military bases and personnel since World War II.

What are the Locations of Military Bases and Installations Operated by the US Military?

• RAF Mildenhall: Suffolk, UK.
• RAF Lakenheath: Suffolk, UK.
• RAF Feltwell: Norfolk, UK.
• RAF Alconbury: Cambridgeshire, UK.
• RAF Molesworth: Cambridgeshire, UK.
• RAF Croughton: Northamptonshire, UK.
• RAF Barford St John: Oxfordshire, UK.
• RAF Fairford, Gloucestershire, UK.
• RAF Welford: Berkshire, UK.
• RAF Menwith Hill: North Yorkshire, UK.
• Blenheim Crescent: Middlesex, UK.
• Naval Support Facility: Diego Garcia.
• RAF Ascension Island: Ascension Island.

In Which Year was the First US Military Base or Installation Constructed in the UK?

The earlier bases constructed by the US were ten airfields on which construction began in September 1942 (Chipping Ongar, Deback, Eye, Glatton, Gosfield, Great Dunmow, Great Saling, Matching, Nuthampstead, and Stansted).

Are US Military Bases and Installations that are Located in the UK considered US Territory or US Property?

They are not considered either US territory or US property.

What Treaties or Legislation Enables the US Military to Operate US Military Bases and Installations on British territory?

• The original agreement allowing the US presence in the UK is loosely defined per the Churchill Truman Accord (post WWII).
• The US Visiting Forces (USVF) based in the UK are governed by the North Atlantic Treaty Organisation (NATO) Status of Forces Agreement 1951 (‘the SOFA’).
• The NATO SOFA governs the activities of the Force but is not a Treaty that authorises access.

Is the US Military Authorised to Hold Military Exercises Out of US Military Bases and Installations that are Located in the UK, in other parts of the UK, or British airspace?

• SOFA governs the activities of the USVF.
• US Forces frequently conduct training exercises both within and outside the military bases and installations made available to them.
• The type of exercise or training being done and its location will normally determine the level of coordination required with the Ministry of Defence (MOD) or other UK Government agencies involved.

Which Branches of the US Military Operate from the US Military Bases and Installations that are Located in the UK?

• US Air Force.
• US Space Force.
• US Army.
• US Navy.
• US Marine Corps.

What US Military Units are associated with the US Military Bases and Installations that are Located in the UK?

• 48th Fighter Wing (48 FW).
• 100th Air to Air Refuelling Wing (100 A2ARW).
• 501st Combat Support Wing (501 CSW).
• 352nd Special Operations Wing (352 SOW).

How Many US Personnel Work in these US Military Bases and Installations?

• Alconbury:
  • 501 CSW: 575.
• Croughton:
  • 501 CSW: 345.
• Fairford:
  • 501 CSW: 16 (and 303).
• Lakenheath:
  • 48 FW: 5,164 (and 240).
• Menwith Hill:
  • 501 CSW: 1,000.
• Mildenhall:
  • 100 A2ARW and 352 SOW: 3,688 (and 151).
• Molesworth:
  • 501 CSW US Air Force: 205.
  • 501 CSW US Army: 106.
  • 501 CSW US Navy: 119.
• London (Embassy and Liaisons):
  • US Embassy: 52.
  • 501 CSW: 48.
• Others in UK (Multiple Locations);
  • 501 CSW: 135.

Notes

• Second figure in brackets refers to temporary assignment personnel.
• The figures shown are made up of US Space Force, US Marine Corps, US Navy, US Army, US Air Force and Civilians working for the US Department of Defence.

Reference

FOI 2022/05107 dated 24 May 2022.