This is a policy briefing prepared by International Crisis Group regarding the expansion of Somali Islamist Radicalisation trends into bordering Kenya. The militant Al-Shabaab movement has built a cross-border presence and a clandestine support network among Muslim populations in the north east and Nairobi and on the coast, and is trying to radicalise and recruit youth from these communities, often capitalising on longstanding grievances against the central state. This problem could grow more severe with the October 2011 decision by the Kenyan government to intervene directly in Somalia. Radicalisation is a grave threat to Kenya’s security and stability. Formulating and executing sound counterradicalisation and de-radicalisation policies before it is too late must be a priority. It would be a profound mistake, however, to view the challenge solely through a counterterrorism lens.