This article is a reaction to the rapid changes many urban areas are undertaking in attempts to counter the contemporary terrorist threat since the devastating events of September 11th. The response of central London authorities both pre‐ and post‐ September 11th is used as the lens through which to view attempts to reduce the real and perceived threat of terrorist attack through the adoption of territorial approaches to security, both physical and technological, which are increasingly being utilized at ever‐expanding spatial scales. It argues that this situation all too often produces a scenario of ‘splintered urbanism’ as security rings are thrown up around carefully selected sections of cities deemed most at risk. It further argues for a balance to be struck between competing concerns for freedom of access, mobility and other democratic freedoms, and the need for cities to adopt increasingly militarized security perspectives in their counter‐terrorism efforts.