Conventional attack on the UK mainland or overseas territories*


Protection of the UK, its citizens, property, and territory, from adversarial states, remains one of the highest priorities of the government. This defence and security protection extends to UK overseas territories and crown dependencies. NATO provides the backbone of the UK’s collective defence within the Euro-Atlantic, however sovereign options are required to support overseas territories that may fall below the NATO Article 5 threshold.


The reasonable worst-case scenario of this risk involves an adversary nation attacking the UK mainland or overseas territories using a combination of conventional missiles and cyber operations. For this scenario, targets are related to infrastructure. Although no population centres are deliberately targeted, a successful attack is likely to result in civilian fatalities as well as members of the emergency services. The economic costs of such a scenario would be high, as well as significant impacts to essential services.

The position on the matrix is held at a higher classification.

*A separate scenario involving a nuclear attack on the UK mainland or UK overseas interests exists and is held at a higher classification.