In May 1941, Gorham and his wife renounced U.S. citizenship and naturalised as Japanese citizens. They apparently chose to do this so that they could remain in Japan, as wartime conditions meant increasing restrictions on foreigners. During World War II, Gorham continued his engineering work at Hitachi, focusing on multicut lathes and jet engines. After the end of the war, the United States government declined to charge him or his wife with treason since they had become Japanese citizens before the war began; in fact, he ended up working in a liaison position with the headquarters of Supreme Commander for the Allied Powers Douglas MacArthur regarding industrial problems.
