The disused Jubilee line platforms at Charing Cross tube station were transformed into a wartime command bunker last week as hundreds of uniformed soldiers descended underground for a major NATO military exercise.
(c) MoD
Known as Arrcade Strike, the exercise was led by the Allied Rapid Reaction Corps (ARRC), NATO’s premier deployable corps headquarters under British Army command.
The operation tested the ARRC’s ability to plan and direct a large-scale conflict involving around 100,000 troops from Britain and allied NATO nations. From deep beneath central London, commanders coordinated operations across land, sea, air, cyberspace and even space.
The scenario was fictional, but only just.
Set four years in the future, it reflected growing concern among military planners that Russia’s threat could peak by the end of the decade. The systems, command structures and tactics being rehearsed, however, are already operational.
As one senior commander put it: “Arrcade Strike is not a conceptual exercise. It is a rehearsal of the plans we already have and a demonstration of our ability to fight and therefore to deter.”
A major focus of the exercise was survivability. Modern military headquarters are increasingly seen as vulnerable targets, forcing armies to rethink where and how command centres are based.
“We have moved from operating in tents and open environments, to commercial buildings, to aircraft hangars, and now to underground locations,” one commander explained during the exercise. “Operating below ground significantly reduces our signature, makes us harder to find, and improves our chances of surviving attack.”
(c) MoD
That shift reflects lessons already emerging from Ukraine and NATO’s eastern flank, where concealment and hardened infrastructure are becoming essential rather than optional.
Charing Cross was selected because the abandoned Tube platforms offered a rare combination of security, scale and location. Hidden beneath one of the busiest parts of London, the site provided enough room for a fully functioning headquarters while proving the concept could operate in the middle of a dense urban environment.
It’s not that they intend to use the tube tunnels as a command centre, but are practising and ironing out the niggles of using tunnels anywhere as bunkers if they need to.
At its peak, around 500 personnel were working underground, processing more than ten terabytes of operational data every day — roughly equivalent to streaming high-definition Netflix continuously for nearly three months.
The exercise also served as the public debut for the British Army’s newest formation, 9 Deep Recce Strike Brigade (9 DRS).
The brigade is designed to locate enemy forces at long range and destroy them before they can act. Its arsenal includes surveillance drones, long-range precision rockets capable of striking targets up to 150km away, and one-way attack drones with ranges of up to 600km.
Supporting all of this is Project Asgard, an AI-powered battlefield management platform that combines data from sensors, satellites and intelligence feeds to help commanders make decisions faster than an opponent can react.
Getting an entire military headquarters into a disused Underground station without attracting attention was itself a logistical exercise.
Major Joe Harris, 14 Squadron RLC, the logistician overseeing the operation, explained that the equipment was moved in unmarked civilian vans to Ruislip at 1.30am before being transferred onto a specialist TfL engineering train — effectively a cargo version of a Tube train fitted with a crane. From there, the equipment was taken directly into Charing Cross, where teams spent a week constructing the underground headquarters alongside 22 Signal Regiment, which installed the communications systems.
“The difference between being here and in an old warehouse, which would be our usual location, is that a warehouse would be a wide-open rectangular space, and this is a constrained layout with a warren of tunnels and train platforms,” Joe said.
“We’ve got to get out of the mindset of Afghanistan, where we move in and create a space from scratch. Now we need to find a ready-made safe space and set ourselves up accordingly.”
(c) MoD
The ARRC plans to continue testing underground headquarters across Britain and Europe over the coming years as NATO works towards creating a fully mission-capable Strategic Reserve Corps by 2030.