Short answer
MI5 leads the work to protect Northern Ireland from threats to national security, especially terrorism, working closely with the PSNI.
What we know Fact
- MI5 took over lead responsibility for national security intelligence in Northern Ireland in 2007.
- It has a regional headquarters in Northern Ireland.
- It investigates threats such as Northern Ireland-related terrorism and works with the PSNI to disrupt attacks.
- MI5 sets the terrorism threat level for Northern Ireland.
