It warned that extremism had emerged as one of the “dominant domestic security and social threats” facing the UK. This was having a “detrimental impact on the fabric of British society,” the report warned, pointing to last summer’s riots and the terrorist attack on a synagogue in Manchester in October. The report warned that every indicator of radicalisation, from hate crimes to belief in conspiracies, has risen over the past decade. It said that “trigger events”, such as issues related to immigration and conflict, had “served as mobilising opportunities” for extremist groups to spread hate and hateful ideologies. The paper,...