The Government has decided to post the UK terror threat level on the home office and MI5 websites. On 1 August, a new public system of alerts will replace the existing mechanism which, despite being secret, was widely leaked and speculated upon.
As with the existing system, the new (slightly simplified) threat levels will have specific meanings for various official and industrial organisations. Government, the security services, the armed forces and other elements of our critical national infrastructure will all have defined actions to take when warnings are issued, and will instructed on how to act when the threat is at a given level.
The difference with this new system is that the public have been made a part of it. Strangely, however, no guidance has been issued on how you should react to the different levels of threat.