The suicide bomb attacks in Brussels are unlikely to be the final operation mounted by the so-called Islamic State on European soil. France's President Hollande says Europe is now at war, so what are the most effective weapons at Europe's disposal? Dominic Grieve was the Attorney General in David Cameron's first term as British prime minister. He is now Chairman of the UK parliament’s Intelligence and security committee. Can Europe be both secure and free?(Photo: Dominic Grieve, MP)