T H E A R M Y A I R F O R C E S I N W O R L D W A R I 1
completed; the specific role of the Army was described in a War
Department operations plan and a concentration plan.1zo
Insofar as general concepts were concerned, RAINBOW No. 5
accepted all the major theses of ABC-I; that is, the assumptions, the
over-all strategy, and the principles governing strategic direction and
theater command were identical. In essence, RAINBOW No. 5 con-
stituted a more detailed plan for the accomplishment of the tasks
assigned to the United States in the staff conversations. For the Army,
M-day would be designated only by direction of the Secretary of
War, though certain tasks of a precautionary nature might precede
M-day or any formal declaration of war.
The plan designated the coastal frontiers and defense commands to
be activated on M-day within areas of U.S. strategic direction, and
the areas to be occupied in Europe. For each command, the mission of
the Army (including air forces) and the Navy was described, and a
detailed breakdown was given, by specific units, of the forces
allocated.
Most Army forces available for M-day were to be deployed either
in Western Hemisphere defense commands or in the Hawaiian and
Philippine coastal frontiers, with strictly defensive missions. The only
exception was in the European theater, and even there, where the
United States was to exert its principal effort, initial operations were
to be preponderantly naval (protection of shipping) and aerial (bom-
bardment of Germany). Hence the Army forces set up for early
deployment in that theater were not large: pursuit units and ground
forces for the defense of US.base areas in the United Kingdom and
for relief of British troops in Iceland and Ireland; a token force
(ground) to aid in defense of England; and the bombardment force
for the air attack on Germany.
In addition to these forces assigned for deployment before or on
M-day, both a strategic and a general reserve were established. It was
understood that even for defensive purposes certain tactical offensives
of a precautionary nature might be required-the President, for ex-
ample, was publicly declaring our disinclination to allow Hitler to
seize certain strategic spots in the Atlantic.121 Hence the strategic
reserve was set up in increments with those tasks in mind: a 2 5 M
Force (that is, a force to be brought into existence on M-day plus 25)
to aid Marines in occupying Dakar or Freetown, or in defending the
Azores, Cape Verde, or Canary Islands against possible Nazi aggres-
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