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War Plan Indigo

Indigo is the color on the electromagnetic spectrum between about 420 and 450 nm in wavelength, placing it between blue and violet. Indigo is a color that the human eye is not very sensitive to so people do not see it very well. It's frequency is between blue and violet, both of which humans see better. Although all the blues in a rainbow do contain some red, there is no place in the rainbow where a deep enough blue combine with enough red to make indigo.

Early in the European conflict both the British and the Germans had recognized what the Vikings had demonstrated ten centuries before, namely, that Iceland was an important steppingstone between Europe and the New World. Hitler several times toyed with the idea of a descent upon the island and laid preliminary plans for it; but to forestall such a move British troops, soon joined by a Canadian force, had landed in Iceland on 10 May 1940. Icelandic annoyance with the British and Canadian garrison, and British losses in the war, which made a withdrawal of the Iceland garrison seem desirable, plus American concern for the Atlantic sea lanes, combined to bring Iceland within the American defense orbit.

Taking a pessimistic view of England's chances of survival the Icelandic Government had, as early as mid-July of 1940, approached the Department of State concerning the possibility of Iceland's coming under the aegis of the Monroe Doctrine and in September and December the question was again raised. In Iceland it was apparently expected that a simple declaration by the United States to the effect that Iceland lay within the western hemisphere, and therefore within range of the Monroe Doctrine, would make the presence of foreign troops unnecessary. If a garrison was required, it was thought that American troops, being those of a nonbelligerent power, would not draw German attacks. And once Iceland was accepted as part of the "Monroe Doctrine Area" it was hoped that a favorable trade agreement could be arranged with the United States. On 11 February 1941 Secretary of War Henry L. Stimson informed the Secretary of State that the War Department shared the latter's views that the United States should "neither discourage nor encourage an approach to this Government by the Government of Iceland."

By the early spring of 1941 the British position in the Mediterranean had become extremely precarious. Weakened by the withdrawal of some 50,000 troops to Greece and surprised by greatly reinforced German and Italian forces, Britain's Army of the Nile was driven back, with serious losses, across the African deserts to the Egyptian border. Disaster in Greece, following hard upon the rout in North Africa, added 11,000 dead and missing to the casualties of the African campaign. There was thus a pressing need for the 20,000 or so British troops tied down in Iceland. Meanwhile the Battle of the Atlantic had taken a critical turn when, in March, German U-boats moved westward into the unprotected gap between the Canadian and British escort areas. Shipping losses mounted steeply. Although the Royal Navy immediately established a patrol and escort staging base in Iceland, a dangerous gap in the ocean defenses remained.

American concern in the protection of the North Atlantic sea lanes, and in the defense of Iceland as well, had been acknowledged in the Anglo-American (ABC) staff conversations of March 1941. Although Britain, in her own interest and on her own initiative, had already committed herself to both tasks, they were recognized as matters of mutual responsibility in the final staff report, the so-called ABC-1 agreement. Britain, it was decided, would provide a garrison for Iceland as long as the United States remained a nonbelligerent; should the United States be forced into the war against the Axis Powers, American troops would then relieve the British garrison. By admitting and accepting this measure of responsibility, however conditional it was, the United States laid itself open to an appeal for assistance whenever Britain should find the defense of Iceland too burdensome. If the United States, instead of awaiting formal entry into the war, was to undertake immediately the responsibility it had accepted for relieving the British troops in Iceland, then British losses in North Africa and Greece could be to some extent replaced without undue strain on British manpower.

Iceland, no less than Britain, was anxious to have the British garrison depart. Intensely nationalistic, proud of their ancient civilization, the Icelanders chafed under the "protective custody" in which they found themselves placed. As long as Canadian troops made up a large part of the garrison force, they had felt that a wholly British contingent would be preferable, but when the Canadians were later replaced by British troops most Icelanders seemed to find their lot no more bearable. As the scope of Germany's aerial blitzkrieg widened, the people of Iceland grew more uneasy; for to be "defended" by one of the belligerent powers, they felt, was an open invitation to attack by the other. The Icelandic Government shared the apprehensions of the people and found further annoyance in Britain's control of Iceland's export trade.

Washington's interest in Iceland had quickened as an outgrowth of the problem of placing American planes and supplies in the hands of the British and as part of the task of making the United States Navy's "neutrality patrol" more effective. On 10 April 1941 President Roosevelt decided to extend the neutrality patrol to the middle of the Atlantic, roughly to the 26th meridian. At the end of the month, the War Plans Division recommended that an Army survey party be sent to Iceland for the specific purpose of preparing detailed plans for its defense. That a declaration of war by Germany would follow the landing of American troops on Iceland, whether by invitation of the respective governments or not, was regarded by War Department planners as almost certain.

The shifting tides of war and strategy had not only created a more urgent need elsewhere for the British troops that were in Iceland, they had also strengthened President Roosevelt's determination to ensure the safety of Britain's North Atlantic supply line. Declaring an unlimited national emergency, the President in a speech on 27 May 1941 promised all possible assistance in getting supplies to Britain. Two days later, in response to an inquiry made by the President not long before, Prime Minister Churchill informed Roosevelt that he would welcome the immediate relief of the British garrison in Iceland.

On the strength of Secretary Stimson's request in the War Council meeting of 3 June, the War Department had hastily resumed the long-dormant preparations for sending a survey party to Iceland, although the head of the War Plans Division and some of his subordinates were opposed to the idea of an Iceland expedition. From that point planning had to proceed on the basis of the two known factors: that approximately 30,000 troops would be required, and that either the 1st or 5th Division would provide the nucleus of the force. In the absence of other data the chief consideration governing the strength and composition of the proposed Iceland garrison was that it must be comparable to the British units for the relief of which the American force was intended. In the preliminary planning and the discussions that took place during this first week in June 1941, the 1st Division was scheduled for the job in lieu of the 5th. The shift of units apparently was made with some misgivings, for the 1st Division was the best equipped infantry division in the Army, the only one that approached a state of readiness for combat involving landings on a hostile shore.

Harbor conditions and the lack of facilities at Reykjavik were recognized as the real limitation. The problem, simply stated, was to place in Iceland, as soon as possible, nearly 30,000 men with 231,554 ship tons of equipment, weapons, and supplies, and to provide thereafter some 25,000 tons of shipping each month for maintenance.

Legal restrictions prohibited the National Guard, members of the Reserve, and men drafted under the Selective Service Act from serving outside the Western Hemisphere and limited their terms of military service to a period of twelve months. For purposes of naval defense the President had placed the Atlantic frontier of the western world, quite arbitrarily, along the 26th meridian, which excluded the whole of Iceland.

On 07 June 1941, General Marshall informed the War Plans Division that the Iceland preparations should be based upon using the 5th Division with a Marine Corps unit for the first wave of the force. Substituting the 5th Division for the more indispensable 1st Division as the basic component of the force and that thus the latter division would once more be available for the role originally assigned to it in the war plans. The new timetable, submitted to the War Department on 16 June, tentatively provided for three convoys sailing at ten-day intervals, beginning 20 August 1941, each carrying 8,500 men.

Planningn challenges were: first, the lack of harbor facilities at Reykjavik and the outports, which would impose limitations on shipping; second, the availability of housing, which was conditioned upon the British evacuating their Nissen huts; and third, the onset of winter gales and snow after late September, which established a deadline for the operation.

On 01 July 1941, the Army-Navy Joint Planning Committee finally completed and submitted to the Joint Board the basic directive for the Iceland operation. Given the short title INDIGO, it was intended to be the definitive joint plan to which all subsequent planning should conform. Unfortunately it emerged stillborn. The plan failed to survive a policy decision taken the very same day, a decision that was partly the culmination of the War Department's approach to the problem and partly the result of the President's fears that the proposed garrison was inadequate.

Heretofore the confusion and the vacillation and the irreconcilable plans had generally arisen over a question of method, of how to transport to Iceland by a definite date a specified number of men with a given amount of supplies and equipment. But the tendency to approach a solution by changing the terms of the proposition gradually developed, and the more pronounced this tendency became, the larger grew the area susceptible to dispute and revision. Shuffling the supply requirements had necessitated several changes in the plan before the INDIGO directive finally established a convoy schedule by cutting back the bulk of reserves to a 90-day level, by setting a 200,000-ton limit on cargo, and by making a corresponding reduction in the number of cargo transports.

It was primarily President Roosevelt's doubt whether there were enough British troops in Iceland which led, paradoxically, to the reduction in size of the American force sent there in 1941. Informed of his views, the British Foreign Office in late June gave a definite pledge that no troops would be withdrawn until both the United States and Britain were satisfied that the defenses of Iceland were secure.

The invitation from Iceland to take over the task of defense, its acceptance by the President, the orders for the marines to resume their voyage (they had been held in Newfoundland for three days in expectation of the Icelandic request), and the decision that the Army would reinforce the British, not relieve them, all came on the same day, 01 July 1941.

The claim was not then made, as it was soon afterward, that the legal restrictions themselves caused the original INDIGO plan to be abandoned; and as for the effect of Congressional controversy over lifting them, if the President had already made up his mind to ask for their removal when he made the Iceland decision on 1 July the War Plans Division had apparently been kept uninformed of his intentions. But the release of the Chief of Staff's biennial report on the morning of Thursday, 3 July, opened the question to public discussion. Immediately the leaders of isolationist opinion let loose a barrage of criticism against General Marshall's recommendation that the twelve-month limitation on the length of service be removed.

On 07 July 1941, Presidential Secretary Stephen Early dropped a guarded hint to the press that a message to Congress asking an extension of the twelve-month limit of service was to be expected. It was almost completely overshadowed by the announcement, simultaneously made, that the marines had landed in Iceland. The Second Echelon was ready to depart by 4 September, almost exactly three months after the decision to launch the operation had been made.

As an ad hoc operational plan the original INDIGO plan was not sufficiently general to accommodate itself to changes in basic conditions; and in its character of a directive it was so detailed as to lack precision. But what effect these failings had, and what the effect would have been had the planning been faultless, is a matter of conjecture; for the INDIGO directives were drawn up in accordance with, and changed to conform to, the projected operations. Thus GHQ was not given, for its Theater of Operations Plan, a clear-cut definition of the limits within which the operations were to be conducted.

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Page last modified: 05-07-2011 02:36:30 Zulu