Unnecessary risks

I fear that, because we are afraid of repeating the mistakes of two World Wars re enemy aliens, we are taking unnecessary risks with terrorism. An inquest into the Linz coffee bar terrorist incident has criticized police or waiting until a victim was shot before storming the place But the British police have admitted that the Manchester bomber was under surveillance by the authorities. Nevertheless he and his family recently visited Libya. It was the same in Westminster. Is this that different from Sydney? There is surely a case for internment of individuals according to profiling?