Photograph of the Security Service Crest Security Service crest
We work closely with a range of other agencies and organisations in seeking to counter threats to national security.
Our work focuses on:
Although publicly available information can be helpful for background purposes, the best way to discover the intentions and actions of organisations and individuals posing a threat to national security is to obtain secret intelligence about their activities. Over time, we collate this information and seek to develop detailed knowledge of target organisations, their key personalities, infrastructure, intentions, plans, and capabilities.
If intelligence is worth recording we ensure that this is done accurately, clearly marking its origin and authenticity, and ensuring that it can be retrieved swiftly. If we assess that a particular threat needs to be investigated, then resources are deployed to obtain further intelligence. Assessments are continually adjusted in light of new intelligence or events.
This whole process of assessment and investigation helps us make decisions about counter action and protective measures. Our judgements of the scale of the various threats to national security and the distribution of our efforts in response are subject to validation by the Home Secretary and the external scrutiny of Parliament. We adjust our priorities according to the national requirements for intelligence, set by Government, drawn up by the Joint Intelligence Committee (JIC) and endorsed by Ministers.