The first formal imperial defence policy dates to 1907, with revisions in 1918, 1923, and 1936. Earlier documents had served similar purposes, but formal codification brought strategic aims into a recurring national planning instrument. The policy assigned the navy the task of forestalling and annihilating an enemy sea force while the army rapidly concentrated to seize the initiative. Those broad instructions did not prescribe every operation, but they framed the doctrine from which interception, attrition, and decisive-battle plans developed.
Notable Point · 56:57-58:27
How imperial defence policy became a recurring planning instrument
Japanese imperial defence policy was formally issued in 1907 and revised in 1918, 1923, and 1936, repeatedly defining the framework for naval and army action.