The keynote of all war planning before 1939 was the strategic concept, required by national policy, of defense of the United States by the United States alone against any and all combinations of foreign powers. Thus of the ten or twelve color plans current and approved in the years between the wars, the one which occasioned the most staff work was not, properly speaking, a war plan at all but instead a "National Position in Readiness" plan called BLUE (United States). Of the others only two called for general mobilization of the armed forces, and these two represented highly improbable developments in international affairs, namely a war against RED (British Empire) or against a coalition of RED and ORANGE (Japan). The most significant plan from a strategic point of view was the ORANGE plan proper, which visualized a major conflict that, although primarily naval, would require the mobilization of more than a million men in the Army. The other war plans provided for actions in comparatively minor emergencies.
In all cases the color plans were simple outlines of missions to be accomplished and Army forces to be mobilized, concentrated, and used in combat in the event that military operations became necessary under the circumstances presupposed in any one of the plans. As strategic planning in a broad sense, the early war plans, with the exception of ORANGE, were virtually meaningless because they bore so little relation to contemporary international political and military alignments. They were valuable, however, as abstract exercises in the technical process of detailed military planning, providing useful training for the officers who drew them up....As far as I know, all armies do this. Just as engineering professors cause their students, for practice, to plan cantilevers, trusses and the like, generals cause their staff officers to plan hypothetical invasions of Hungary and Costa Rica. Unlike the professors, however, the Army secretly archives the plans. Most plans are never used; but, occasionally, in an emergency, a plan may be snatched from the archive and put into sudden action.
It is more likely, of course, that the plan which actually gets used will have been prepared before action with greater care.
By 1940 [when World War II had begun on both sides of the Old World but the United States was not yet openly in the fight] the color plans had been largely superseded by the more comprehensive RAINBOW plans, which provided a variety of military courses of action to meet the real strategic situation imposed by Axis aggression.Still, even an obscure plan can influence the course of a war, whether or not the plan as such is ultimately employed. William L. Shirer recounts:
Shortly before Christmas [1939, Alfred Rosenberg, head of the German Nazi party's Foreign Affairs Department] dispatched a special agent ... to Norway,... and over the holidays the handful of officers at OKW who were in the know began working on "Study North," as the plans were first called.
[Two months later], Hitler ... sent for [Gen. Nikolaus von Falkenhorst], who ... commanded an army corps in the west....
Falkenhorst later described in an interrogation at Nuremberg their first meeting at the Chancellery on the morning of February 21, which was not without its amusing aspects. Falkenhorst had never even heard of the "North" operation and this was the first time he had faced the Nazi warlord, who apparently did not awe him as he had all the other generals.
"I was made to sit down," he recounted at Nuremberg. "Then I had to tell the Fuehrer about the operations in Finland in 1918.... He said: 'sit down and just tell me how it was,' and I did.
"Then we got up and he led me to a table that was covered with maps. He said: '... The Reich Government has knowledge that the British intend to make a landing in Norway....'"
[T]he General, to his surprise, found himself appointed then and there [to carry out the invasion of Norway] as commander in chief. The Army, Hitler added, would put five divisions at his disposal. The idea was to seize the main Norwegian ports.
At noon the warlord dismissed Falkenhorst and told him to report back at 5 p.m. with his plans for the occupation of Norway.
"I went out and bought a Baedeker, a travel guide," Falkenhorst explained at Nuremberg, "in order to find out just what Norway was like. I didn't have any idea.... Then I went to my hotel room and I worked on this Baedeker.... At 5 p.m. I went back to the Fuehrer."
The General's plans, worked out from an old Baedeker—he was never shown the plans worked out by OKW—were, as can be imagined, somewhat sketchy, but they seem to have satisfied Hitler. One division was to be allotted to each of Norway's five principal harbors, Oslo, Stavanger, Bergen, Trondheim and Narvik. "There wasn't much else you could do," Falkenhorst said later, "because they were the large harbors." After being sworn to secrecy and urged "to hurry up," the General was again dismissed and thereupon set to work.Apparently, the nonlinear way in which plans interact with unforeseen events can be complex. No formula can explain it, but stories like these can help one to understand.
The story of Falkenhorst and the Baedeker seems worth telling in any case. I do not suppose that the Norwegians found it too amusing when the German Army actually invaded (as indeed the German army did, 77 years ago next month), but, you know: a Baedeker? As though the General were looking for aught but a cozy Norwegian hotel in which to spend the night.
And before that, on the American side during the 1930's, the U.S. Army's chief strategic study seems to have been a plan to parry a hypothetical joint invasion of the United States by whom? By Britain and Japan!
In the shadow of the (now almost forgotten) Washington Naval Conference of 1922, I suppose that the idea was that, if the U.S. could parry a joint invasion by Britain and Japan, then the U.S. could probably parry other invasions, as well; but war with Britain and Japan does nevertheless seem formally to have been the plan.