The reality of terrorist attacks on civilian targets coincides with the rise in the level of accountability required for use of the public resources devoted to security. Allocating resources to combat the usual crimes and potential terrorist attacks is a big challenge for the Metropolitan Police. Other big challenges are how to balance the need for security with the normal freedoms expected in a parliamentary democracy and how to react to potential terrorist attacks in a manner that is commensurate with the level of the threat and that reassures rather than “terrorises” citizens and excessively disrupts the normal functioning of society. The work of other important actors in the society, such as the media, is important to achieving the right balance.