Independent assessment of the UK’s capability and capacity devoted to countering jihadist terrorism is limited owing to a scarcity of publicly available data and published academic research. The UK has a long-standing, refined Counter Terrorism (CT) strategy (‘CONTEST’) and Rule of Law CT Model that is world leading and replicated by countries around the world. The UK has a less well- developed Counter Extremism (CVE) strategy. The capability of the UK’s government, police (National Police Counter Terrorism Network (NPCTN)) and intelligence agencies (MI5, MI6 and GCHQ) for countering jihadi terrorism is widely considered to be exemplary. A significant proportion of the UK CT capacity (i.e., human resources and finances) is assigned to dealing with the resultant symptoms of jihadist terrorism rather than the underlying root causes of it. Successive UK governments led by different political parties have uplifted overall CT capacity in real terms over the past twenty years. The implicit capability and capacity of Muslim civil society within the UK to deal with the root causes of jihadist terrorism is considered weak, rendering the former vulnerable to extremism.