T H E A I R C O R P S P R E P A R E S F O R W A R , 1 9 3 9 - 4 1
the role of the Army air arm in the interception of enemy naval
force^,'^ but that mission had been a leading factor in the Air Corps’
emphasis on the long-range bomber. N o w the new threats to hemi-
sphere security added less debatable obligations, which the Air Corps
proposed to meet with a force of heavy bombers.
Actually, Army air leaders had anticipated somewhat the President’s
public statements of our changing concepts of defense. In June 1938,
the Air Corps Board had begun a study on the “Air Corps Mission
under the Monroe Doctrine.” 5 2 During the following March basic
air doctrines were restated, so that the most important task became
defense against air attacks, to be achieved by the “destruction of enemy
aviation at its bases.” 53 In June 1940, the Air Corps described its role
in hemisphere defense as entailing six specific missions in the following
order of importance: to ( I ) deny the establishment of hostile air bases
in the Americas; ( 2 ) defeat hostile air forces lodged in the hemisphere
by attacking their bases; ( 3 ) defeat hostile air forces by aerial combat;
(4) prevent the landing of expeditionary forces by attacking trans-
ports and supply ships; ( 5 ) co-operate with the mobile army in ground
operations; and ( 6 ) operate in support of or in lieu of US. Navy
forces against hostile fleet^.'^
In each case the statement of doctrine was made to guide the ex-
penditure of funds authorized to the Air Corps for meeting its new
obligations. T h e accepted concept of the air mission which subordi-
nated local air defense and close support of ground forces to long-
range counterair activities was reflected in the practical measures
taken. Units of the GHQ Air Force did participate, with the inade-
quate equipment available, in Army maneuvers in I 940-41, and by the
time war came, the AAF had taken certain steps, largely modeled on
British experience, for local air defense of certain vital areas.” But the
main concern of Army airmen was in defense at a distance by means
of the mobile striking force. This demanded, as they reiterated on
numerous occasions, a wider radius of action, which could be achieved
by increasing the range of their bombers and acquiring new bases,
strategically located. In the summer of 1938 our best heavy bomber
was the B-17, with a theoretical useful radius of 1,000 miles; a new
experimental model, the XB-I 5, seemed to promise better perform-
ance. T h e Air Corps Board in October recommended as a minimum
requirement a 1,500-mile bomber.55 In June 1939, another air board
* See below, Chap. 8.
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