was, in many respects, an effort to prioritize these roles and missions and to
fashion them into a coherent grammar.
It is an oversimplification to see inter-war air power theories as a running
debate between two major schools of thought: the ground-support advocates and
the long-range bombing enthusiasts. As historians now make clear, the thinking
in the Air Corps Tactical School (ACTS) evolved during the inter-war years: from
an initial emphasis on achieving air superiority; to providing close air support to
ground operations, that is acting as ‘flying artillery’; to the use of precision
daylight bombing to destroy a country’s vital production and distribution
areas, and presumably breaking its will to fight in the process. 31 By the late
1930s, bombing enthusiasts dominated American air power theory, with ACTS
doctrine even going so far as suggesting that in the majority of cases the modern
bomber would be able to fight its way through enemy air defences and arrive on
target and deliver its payload. Similarly, US military observers who witnessed the
Battle of Britain in 1940 pointed out that, while British and German bombers
proved susceptible to fighters, American bombers were much better armed, and
would be flying at a higher altitude, and thus the lessons of that battle did not
pertain. 32 By the attack on Pearl Harbor, American operational art in the air had
settled on a grammar of war that rested on a number of nested, and vulnerable,
assumptions: that a nation’s vital areas could be identified, and hit from high
altitude; that once hit, they could be destroyed; and that, if destroyed, the result
would be the collapse of the enemy’s will to resist; and that fighters need not
escort long-range, high-altitude bombers. 33 This grammar would encounter
much need for refinement during the war, but would not receive it. 34
Despite the US navy’s experience with submarine chasing in the Great War, it
reaffirmed the validity of Mahan’s basic concept that the primary objective of
operations at sea was the ‘destruction of the enemy’s main force’. 35 The opera-
tional value of the submarine was not lost on the Americans. However, ethical,
legal, and technical issues slowed its integration. The submarine was considered
by many to be unethical for a variety of reasons, not least of which was that
submarines were too small to take on crews and passengers of the vessels they
sunk; nor were their own crews large enough to take control of vessels willing to
surrender as an alternative to being sunk. War on commerce, sinking merchant
vessels, was not lawful. Technological issues with range, depth, speed, and torpe-
do development also had to be resolved, but fiscal restraints essentially slowed
technological progress. These issues notwithstanding, American political and
military leaders did not want to give up on the submarine, particularly as long
as the Japanese continued to add them to their own inventory. Still, the con-
straints were such that US operational planners considered submarines suitable
for two missions only: coastal protection and fleet operations (attacks against
warships); submarines were to attack only heavy warships, such as battleships and
aircraft carriers. 36
The US navy did anticipate the operational need for aircraft carriers: early on,
it realized it would have to take its air support with it in the vast expanses of
the Pacific Ocean, and it would need to bring enough of it to fight an enemy’s
144 The Evolution of Operational Art