Mission and duties The PJHQ's mission is as follows: PJHQ operates cyber operations in coordination with the Government Communications Headquarters in Cheltenham. There are certain areas that the headquarters will not be involved in: Strategic Nuclear Deterrent Defence of the UK Home Base, Territorial Waters and Airspace Northern Ireland Counter-terrorism in UK (Home Office) NATO Article V (General War) (NATO Military Command Structure) As of November 2022, there were 567 military and civil service personnel assigned to PJHQ. Commanders The Chief of Joint Operations (CJO) is the appointment held by the three star ranked officer that leads PJHQ. See also Northwood Headquarters References Vice Admiral Sir Ian Garnett, "My Job: The Challenge of Joint Command," RUSI Journal, August 1999 Vice Admiral Sir Ian Garnett, "PJHQ: The Heart of UK Defence Capability," RUSI Journal, April 2000 External links Buildings and structures in Three Rivers District Joint military units and formations of the United Kingdom Military headquarters in the United Kingdom Military installations in England Military units and formations established in 1996 Military units and formations in Hertfordshire Military history of London UK