Blake was the senior Allied officer present during the first air raids on Darwin on 19 February 1942. In the wake of the initial Japanese raids—and fearing a surface attack—Blake decided to remove all Allied forces from central Darwin and other coastal areas. He was later criticised for this decision, as withdrawing from a major supply node was considered a cardinal error in military theory. Later that year, as a major Allied build-up in northern Australia got underway, Blake was moved to the position of General Officer Commanding, Lines of Communication, Northern Territory Area.