As war clouds gathered in the Pacific, the fleet increased the tempo of its training operations. Idaho carried out fleet tactics and gunnery exercises regularly until arriving with the battle fleet at Pearl Harbor on 1 July 1940. The ship sailed for Hampton Roads on 6 June 1941 to perform Atlantic neutrality patrol, a vital part of US policy in the early days of the European fighting. She moved to Iceland in September to protect American advance bases and was on station at Hvalfjörður when the Japanese attack on Pearl Harbor on 7 December catapulted America into the war.
Note: David Bell (RADM) served on the Colorado and Idaho before WWII and transferred to Submarine Service in 1940.