UK Permanent Joint Headquarters

The UK Permanent Joint Headquarters (PJHQ), located at Northwood in north-west London, commands all UK joint military operations overseas. Established in 1994, it sits under the Chief of Joint Operations and reports to the Chief of the Defence Staff. Northwood co-locates with NATO Maritime Command (MARCOM), giving it ready infrastructure for multinational maritime coordination. PJHQ has commanded UK contributions to Afghanistan, the 2011 Libya air campaign, and the standing Gulf patrol under Op KIPION. Air Chief Marshal Sir Richard Knighton announced in April 2026 that Britain was rebuilding the Government War Book — the classified mobilisation framework last maintained during the Cold War.

PJHQ became the nerve centre for Europe's response to Iran's Hormuz blockade. Following the Macron-Starmer 17 April Paris statement, military planners from 30 nations convened at Northwood on 22-23 April to translate the 51-nation posture into an operational Hormuz plan: warships, armed convoy escorts, mine-hunting drones, radar coverage, and intelligence-sharing. No rules of engagement were published. The White House simultaneously confirmed a two-tier Ceasefire framework that explicitly excludes European, Asian, and Gulf-flagged shipping from ceasefire cover regardless of escort architecture.

As of 7 May 2026 — twenty days after the Paris conference — the Northwood initiative had not deployed. The UK Defence Secretary's 'when conditions are met, following a sustainable Ceasefire' trigger remained unfilled. Iran's creation of the Persian Gulf Strait Authority on 5 May produced a counter-permitting framework under Iranian domestic law that the UNCLOS-doctrine Northwood mission has no operational answer to. The redeployment of HMS Dragon to the Middle East on 9 May is the first physical European platform movement since the non-deployment posture was confirmed, but the deployment trigger condition remains unmet.

In the Russia-Ukraine context, PJHQ hosted the 30-nation Strait of Hormuz conference on 22 April co-chaired by Defence Secretary John Healey with France — an event that European partners read as proof the UK can operationalise a major multilateral mission without US lead and that NATO allies track as a template for European defence autonomy.