 Complete the following phrase:  Before he retired as MI5s wartime Director General in May 1946, David Petrie offered an assessment of the threat of Jewish terrorism in Europe and a warning: the red light is definitely showing. The alert was confirmed by his successor Sir Percy Sillitoe in August and September, when he designated the Irgun and Lehi as the possibly planning to assassinate prominent English figures outside the Middle East. MI5 considered Mandatory Palestine a priority within the British Empire and had Defence Security Officers DSO stationed within the Mandate, working with local criminal investigation departments CID as well as MI5s sister agency the Secret Intelligence Service SIS, to collect intel on Jewish terrorist threats to Britain. Their sources warned that the Irgun and Lehi were targeting British personnel outside Mandatory Palestine. MI5 were obliged to take these threats seriously: on 22 July 1946, the Irgun 