Foreign Relations of the United States, The Conferences at Washington, 1941–1942, and Casablanca, 1943

Defense Files

Report by the Planning Committee of the United States and British Chiefs of Staff

secret
United States: ABC–4/2
British: WW(JPC)2

[Washington, December 26, 1941.]¹

Project—Gymnast

We submit below a provisional examination of the project for joint operations in Northwest Africa. Our examination is based on the following hypotheses:—

a. That we receive an actual invitation or reasonable assurance there will be only token resistance.

b. That owing to their pre-occupations on the Eastern front, it would take the Germans six weeks to prepare to invade Spain, the forces now in France being unsuitable, and that without Spanish cooperation it would take them about a further six weeks to become firmly established with land and air forces in the South of Spain after they had crossed the Pyrenees. We therefore anticipate a period of about three months before a heavy scale of attack could be mounted against French North Africa from Spain. Spain would probably offer no very effective resistance on the mainland to a German invasion, but would not give the Germans free entry and full facilities. Once the mainland had been invaded our forces would probably be admitted freely into Spanish Morocco.

c. That the Germans are not established in French North Africa in sufficient strength to oppose effectively the occupation of French Morocco.

Objective.

We consider our primary object is to establish ourselves in Northern French Morocco as quickly as possible. This would provide a base from which Spanish Morocco could be occupied at short notice and thus block Germany’s line of advance from Spain. The area would also form a base from which Allied control of all North Africa could be extended.

Base.

The only suitable main base in the area is Casablanca. This port is well developed, served by railways and roads, and lies outside the Straits of Gibraltar. It would be unsound to use as a main base any port inside the Straits as the sea communications to it from the Atlantic would be liable to interruption once the Germans reached South Spain. Initially, owing to scarcity of anti-aircraft defenses and air forces, a single main base must be used for the whole force in North Africa.

Establishment of Base.

There is the possibility of at least token resistance by French forces at Casablanca, which has a considerable garrison and coast defenses. The first force to enter must, therefore, be combat loaded. The United States Marine Division is eminently suitable for this task, and there would be much greater likelihood of French acquiescence in the entry of American forces rather than British.

Support to French in Tunisia.

The immediate result of our forces gaining an entry in Western Morocco, or perhaps a condition of their entry, would be a demand from the French for support against a German threat in Tunisia. We must, therefore, have a suitable force prepared to meet this. This might consist of an Armored Brigade, an Infantry Brigade, two Anti-aircraft Regiments, and three Fighter Squadrons. The forces should be ready to go straight through by sea to, say, Algiers almost simultaneously with the arrival of the advance guard at Casablanca.

Defense of Moroccan Area.

It will be essential to get sufficient forces into the Casablanca area in the early stages to avoid the possibility of the expedition being driven out by German air forces operating from Southern Spain. This points to the very early establishment of adequate air forces and anti-aircraft defenses.

The early arrival of a substantial Army contingent is also essential in order to rally the French and Spanish forces and secure the key positions in Morocco.

The joint forces which we should aim at landing during the first three months are estimated at:—

1	Marine (combat loaded) Amphibious Division
3	Infantry Divisions
2	Armored Divisions
320	First line fighter aircraft
57	First line medium bomber aircraft
57	First line light bomber aircraft
63	First line observation aircraft
120	Heavy anti-aircraft guns
216	Light anti-aircraft guns
	Base and L. of C. units

As further forces become available, all points of entry along the coast will be secured.

Total Forces Required.

The total forces ultimately required to hold French North Africa against possible German attacks through Spain and Italy, and to open the Mediterranean route by providing air cover along the coast, will depend on the assistance that may be furnished by the French and Spanish. The combined British and United States forces might amount to about:

2½–2	Armored Divisions
5–3	Infantry Divisions
	Anti-aircraft weapons (350 heavy and 700 light)
First line aircraft:
800	Pursuit
105	Heavy Bombardment
228	Medium Bombardment
171	Light Bombardment
100	Naval Patrol

Joint American-British Effort Necessary.

Neither country has sufficient forces available to undertake the whole commitment single-handed in a short time. It must, therefore, be a joint expedition. At present the area is one of British strategic responsibility, as defined in ABC–1.² As soon as decision is reached on the operation, it will be necessary to determine responsibility for command so that detailed planning can proceed.

Naval Forces

British.

Unless there is reason to believe that enemy surface units are loose in the Atlantic, close protection of British convoys by heavy ships or aircraft carriers will not be essential. Protection provided by the Home Fleet watching the northern passages and by Force H in the Gibraltar area should be sufficient.

There will probably be 6 British convoys, each divided into a fast and slow portion, sailing from the United Kingdom at about fortnightly intervals. This amounts to doubling the rate of sailing of normal United Kingdom to Cape convoys and the extra escorts will have to be withdrawn from trade protection for a considerable period.

United States.

The U. S. Atlantic Fleet will provide appropriate protection and support for the transit and landing of U. S. Expeditionary Forces.

American Convoy Escorts.

a. Advance American Division—

One Marine Division embarked in 15 vessels escorted by units from Task Force Three.

b. Remainder of initial U. S. forces—

Three convoys at about one month intervals, escorted by units withdrawn from Task Forces Three and Four. Successive logistic convoys require escorts withdrawn from Task Force Four.

Timings.

D–1 is the day on which the order is given to mount the expedition.

a. U. S. Forces

The U. S. Marine Division could reach Casablanca on D–20.

b. British Forces

The first British convoy could reach Algiers on D . . . ., or Casablanca on D . . . . . Subsequently the despatch of the remaining British forces, totalling 1 armored and 2 infantry divisions with ancillary troops would take about another . . . . weeks. Its movement would therefore be complete about D . . . . .

Summary of Plan.

a. U. S. Marine Division, combat loaded and closely supported by United States Naval forces, to secure an entry into Casablanca, against sporadic opposition if necessary.

b. A British force consisting of:—

• 1 Armored Brigade,
• 1 Infantry Brigade Group,
• 2 Anti-aircraft Regiments,
• 3 Fighter Squadrons,

to be ready to move in practically simultaneously with a to Tunisia in case the French demand support in that area; otherwise into Casablanca in support of the advance guard.

c. Main body to follow a and b:—

• 1 American Army Division.
• 1 American Armored Division.
• 2 British Divisions.
• 1 British Armored Division (less detachments in b).
• Air Forces:
  • 320 First line fighter aircraft
  • 57 First line medium bomber aircraft
  • 57 First line light bomber aircraft
  • 63 First line observation aircraft.

d. Base and L. of C. organizations. Air defenses of the base area to be found by the British initially.

Each country to provide its own domestic base administrative services, sharing the base area and port facilities.

U. S. to provide as high a proportion of engineer, technical, stevedore, and labor units for development of static base installations, aerodromes, etc.

The ultimate force to be built up as rapidly as possible.

1. The report bears no date but it was submitted on December 26 and was attached as Annex 2 to JCCSs–3; see ante, p. 98. The following statement appears at the head of the report: “This paper was not approved but was returned to the Joint Planning Committee for reconsideration and resubmission for further consideration.” Further consideration was given to the report at the meeting of the Chiefs of Staff on December 31; see ante, p. 146.
2. For explanation of ABC–1, see ante, p. 16, footnote 2.