A new approach is needed to manage the UK's increasingly nebulous terrorism threat, argues George Glover. The UK's terrorism definition relies on a determination of what ideological or political cause an individual or group is trying to advance. However, the predominance of self-initiated terrorists and the omnipresence of the internet in everyday life are challenging this approach. A better approach would more clearly demarcate terrorism from extremism, to provide the UK counterterrorism community with more robust tools to challenge a threat that is harder to understand.