on the German military bandwagon, Tokyo decided firmly not to abandon its recent
neutrality pact with Moscow. This seemed to be a prudent case of ‘heads we win and tails
we also win’. Should Germany defeat the Soviet Union, then Japan would face no threat
from the north, which would be a highly satisfactory situation. Should the Soviet Union
resist successfully (an unlikely possibility, but one that could not be ruled out), then again
Japan would not be troubled by a Soviet threat, because the USSR would be far too
preoccupied with Germany to be at all interested in fighting Japan for many years to
come. Furthermore, should the Soviet Union defeat Germany, it would be prudent for
Japan not to have lined up as an active belligerent in that conflict.
Japan adopted a necessarily limited strategy for limited objectives. As just noted, it
assumed that it would not have to fight Russia. Conveniently, Germany had reshaped
Japan’s strategic context by both removing the Soviet menace, for a while at least, and
occupying British and American strategic attention in Europe, even though the United
States was yet to enter the war. Japan’s strategic grand design in late 1941 was to seize
by force what it termed the Southern Resources Area of South East Asia, primarily the
Dutch East Indies and Malaya. Then Japan would construct a defensible perimeter to
protect the greatly expanded geographical scope of the new Japanese Empire. From
31 January 1941, Tokyo began referring officially to its imperium, actual and intended,
as the ‘Greater East Asian Co-prosperity Sphere’. (Strategic history is well populated
with such self-serving euphemisms for exploitative political designs.) Japanese naval and
military planners were confident that they could make the necessary gains in a campaign
of only five months’ duration. In this, if in little else, they proved correct.
For this huge smash-and-grab operation to the south to be strategically feasible,
the Japanese Navy reasoned that it must disable or otherwise neutralize the only armed
force in the Pacific that, in theory at least, might offer effective opposition. That threat,
of course, was the US Navy, forward-based on Oahu at Pearl Harbor, as well as the long-
range, land-based air power of the US Army Air Corps’ B-17s, based in the Philippines.
With those assets neutralized, nothing could hinder the brief but highly ambitious march
of conquest. The Philippines were a vital military objective for Japan both because of
General Douglas MacArthur’s B-17s and, more fundamentally, because geostrategi-
cally the islands sat astride Japan’s crucial sea lines of communication to the Southern
Resources Area of South East Asia. In short, there was never any prospect of Japan
restricting its attacks to Dutch and British territories alone and leaving American assets
untouched. Not only was the United States the leader of the anti-Japanese ABCD
coalition, but its brief imperial moment at the end of the nineteenth century had
bequeathed it political responsibilities which happened to lie directly in the path of
Japanese expansion.
The Japanese plan for the security of its expanded empire comprised the following
essential elements: establish an extensive maritime defence perimeter in the Central and
South Pacific; provide strong garrisons, including land-based air power, for selected
islands on and behind that perimeter, for defence in depth; and support those otherwise
isolated garrisons with the Imperial Navy. From such advanced, fortified bases as Rabaul
in New Britain and Truk in the Caroline Islands, the fleet, operating from a central
position, would enjoy the Napoleonic advantage of interior lines of communication.
So much for the necessarily maritime menace from the east. What about the south and
the west?
World War II in Asia–Pacific, II 169