CEP Managing Director Madeleine Joelson and CEP Managing Director Daniel Roth write: "The United Kingdom just banned Hizb-ut Tahrir (HT), an extremist Islamist group with affiliates in at least 32 countries, including the United States, that calls for re-establishing the Islamic Caliphate and implementing Sharia (Islamic law). Given its outsized role in radicalizing several convicted terrorists, including notorious ISIS executioner “Jihadi John,” HT Britain has a far more notorious reputation than its still-active Transatlantic cousin, HT America."