A satellite communications dish outside the Government Communications Headquarters (GCHQ) in Cheltenham, Gloucestershire. GCHQ is one of the three UK Intelligence Agencies and forms a crucial part of the UK’s National Intelligence and Security machinery. The National Security Strategy sets out the challenges of a changing and uncertain world and places cyber attack in the top tier of risks, alongside international terrorism, a major industrial accident or natural disaster, and international military crisis. GCHQ, in concert with Security Service (also known as MI5) and the Secret Intelligence Service (also known as MI6) play a key role across all of these areas and more. Their work drives the UK Government’s response to world events and enables strategic goals overseas.