Temperer

Operation Temperer is a British government plan to deploy troops to support and free up police officers in key locations following a major terrorist attack or major public disorder. It was put into effect for the first time on 22 May 2017 following the bombing of an Ariana Grande concert at Manchester Arena, and for a second time following the Parsons Green bombing. HQ Standing Joint Commander (UK) is militarily responsible for directing the deployment, if ordered.