Defense Files

The Office of the Chief of Naval Operations to the Naval Staff, British Joint Staff Mission 1


Subject: ABC–1; modification of.2

1. In view of the changed situation in the Pacific Area, the Chief of Naval Operations has made certain changes in the disposition of United States naval forces, and the tasks assigned the U.S. Pacific Fleet, that will require modification in ABC–1.

2. The tasks now assigned the Pacific Fleet are as follows:

Protect the sea communications of the Associated Powers by escorting, covering, and patrolling as required by circumstances, and by destroying enemy raiding forces;
Support the Army in the defense of the Hawaiian coastal frontier in category of Defense “D”;
Defend Samoa, Midway, Johnston Island and Palmyra Island, category of Defense “D”;
Defend Wake, category of defense “C”;
Raid enemy sea communications and positions;
Destroy Axis sea communications by capturing or destroying vessels trading directly or indirectly with the enemy;
Protect the territory of the Associated Powers in the Pacific area east of the 180th meridian, and prevent the extension of enemy military power into the Western Hemisphere by destroying hostile expeditions and by supporting land and air forces in denying the enemy the use of land positions in that hemisphere;
Cover the operations of the naval coastal frontier forces and the Canadian local defense forces;
Establish fleet control zones, defining their limits from time to time as circumstances require;
Route shipping of Associated Powers within the fleet control zones.

3. United States naval forces in the Atlantic Ocean have been directed to proceed for assignment as follows:

3 BB —U.S. Pacific Fleet
1 CV —“ “
9 DD —““
36 VPB —““
12 OSS —Fifteenth Naval District.

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4. Until the present situation in the Pacific Ocean becomes more favorable, the Pacific Fleet can not undertake the following tasks of ABC–1:

Support the forces of the Associated Powers in the Far East area by diverting enemy strength from the Malay barrier through the denial and capture of positions in the Marshalls;
Support British Naval Forces in the area south of the Equator, as far west as longitude 155° east;
Prepare to capture and establish control over the Caroline and Marshall Island area.

5. The reduction in United States naval forces in the Atlantic Ocean and the present requirements for escorts in the Western Atlantic Area will delay the furnishing of units, for the following purposes:

United Kingdom and British Home Waters
Northwest Escort Force.
North Atlantic Area
United States Gibraltar Force.

  1. The letter was addressed to the Chief Staff Officer of the British Naval Staff and was signed by L. R. McDowell, Commander, USN, as Secretary for Collaboration.
  2. ABC–1” was the short title for the report, dated March 27, 1941, entitled “United States-British Staff Conversations”. It is reproduced in Pearl Harbor Attack: Hearings before the Joint Committee on the Investigation of the Pearl Harbor Attack, 79th Cong., 1st sess. (Washington: U.S. Government Printing Office, 1946), pt. 15, pp. 1485–1541. See also the account of the staff conversations in Mark S. Watson, Chief of Staff: Prewar Plans and Preparations (Washington: U.S. Government Printing Office, 1950), pp. 374–382.