The Army Air Forces in World War II, Vol. 1 (archived PDF)

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
Watt, the British radar expert, examined Panama defenses and reported
the existence of disturbing weaknesses. The canal, in the opinion of
the British observer, fully justified the concern being shown for its
safety, for it was “unique in the world, possessing only four vital
points, each of small area, but each so fragile that a single projectile
on any of the four could cut this vital line of communications, and
two projectiles on any one of three could prevent its re-establishment
within two years.” 16’ He agreed with American strategists that the
most probable form of attack was a carrier-based raid from the Pacific
and estimated that the Japanese could well afford to sacrifice four
carriers in an attempt to block the use of the canal. Secretary Stimson
reported to President Roosevelt his conviction that the planes from
even one carrier could cripple the canal and that if two or more car-
riers participated in an attack there would be a strong probability of
success. Some means of intercepting carriers far to the west of Panama
was urgently needed, because once “a carrier has released its planes
for attack, no subsequent means of defense against those planes can
sufficiently ensure the safety of the Canal.” 162 An adequate defense
required early detection-and destruction-of enemy carriers at dis-
tances of 500 to 1,000 miles offshore, and since shore-based radars
could not reach that distance, the only solution was long-range aerial
patrol. Even with such surveillance, a carrier might escape notice long
enough to launch its planes, and therefore patrols would need to be
supplemented by an effective cordon of coastal radars to provide a
twenty-minute warning to alert fighters and antiaircraft batteries for
a “last-ditch” defense of the canal.
An adequate patrol on the Pacific side of the canal would require
coverage of an arc of 400-mile depth extending from an inner semi-
circle 600 nautical miles west of Panama to an outer limit of 1,000
miles and from the coast of southern Mexico to northern Peru.16sT o
patrol this extensive zone, aircrews needed the assistance of ASV
radar, which could detect ships a t distances of twenty-five to fifty
miles, and of bases at Tehuantepec in Mexico, at the city of Guate-
mala or San JosC in Guatemala, on the Galapagos Islands, at Salinas in
Ecuador, and a t Talara in Peru.” Of this proposed chain, only the
bases at the city of Guatemala and Salinas were in use at the time of
Mr. Stimson’s visit to the Canal Zone. A field in the Galapagos was
under construction in accordance with an agreement with Ecuador
‘See map on opposite page.
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