The series of defeats suffered by the Japanese military during the second half of 1942 and 1943 led to the introduction of policies to protect civilians from air attack. These measures anticipated the commencement of attacks on the Japanese home islands if the Mariana Islands were captured by the United States.[3] In late 1943 the government of Japan developed plans to evacuate non-essential personnel from Tokyo, Nagoya, Osaka and the cities in northern Kyushu.