Darren (No. 22),
The IJA was extremely parsimonious in allocating troops to the Pacific theater, which they in general viewed as an IJN concern. For 1941-late 42, the Japanese Army wanted to have lots of troops available in Manchuria in case the “persimmon ripened,” as they put it, in Germany’s war with Russia, so that in the event of Soviet collapse, the Japanese could grab part of Siberia. There was a big build up from late 1940 on which did not reach its peak till 1942.
The army allotted only 12 or so division equivalents, plus supports (out of the 51 it had in late 41) to overrunning the “southern areas” — Philippines, Dutch East Indies, Malaya and other points of interest in South East Asia, and the army was extremely reluctant to part with more. (Reading about the early campaigns, one is left amazed at the relative paucity of Japanese forces successfully used to seize such vast spaces — shows how unprepared the allies were for war).
Later, the IJA vetoed a number of IJN proposals that involved bigger troop committments (e.g. invasion of Ceylon — the troops went to Burma instead, which did interest the Army b/c of the war in China; as well as vetoing any efforts towards an invasion of Australia). Australia was, for shipping reasons, a fantasy anyway, as was Hawaii, but they also turned down bigger efforts in the South Pacific in 1942 that might have borne fruit, and they didn’t fortify their conquests as much as they should have.
The Army and Navy had the worst of relations, and generally lied to each other about progress on the several fronts — the Navy, for example, did not tell the Army the details of Midway. They governed planning not by orders issued by a combined staff, but by “Central Agreements” which were negotiated like international treaties. They ran separate military production programs and effectively fought two different wars.
By the time the Army was more interested in releasing troops to the Pacific, the war was a good way to being lost, and, thanks to multiple demands and the US submarine campaign, it was increasingly hard to find the shipping to move the troops, let alone supply them. Lots of troops were ultimately taken out of Manchuria — some went to the Pacific (Iwo, Okinawa, Philippines, Mariana Islands got most late war), some to China — the IJA launched a huge offensive there in 1944, somewhat because of the B-29 raids from the Chinese fields, as an earlier commenter pointed out, but also because the Chinese were an enemy that could be gotten to without swimming.
Alvin D. Coox’s Nomonhan is pretty good on Japan’s plans in Manchuria, and his book with Saburo Hayashi, Kogun — sets out the IJA’s view of the war.
