Unless I’m mistaken on one or more facts, after the unconditional surrender of Japan in August 1945, and the subsequent deposing and execution for war crimes of Japan’s top leaders, Japan more or less did not possess an independent government until the drawing up and adopting of its postwar constitution. So in the interim when the USA was governing Japan, how was this governance styled under US constitutional law? To my naive understanding the Eighteenth Century Framers of the constitution presumed that even a defeated enemy still retained an independent government, and that they never anticipated the “total surrender” doctrine of annihilating a regime; at most, there would be a rapid deposition with new rulers recognized as the “rightful” government.
Was Japan now a US territory? Was some token rump of the pre-surrender government supposedly what the USA was treating with? Did Japan revert to a monarchy in the person of the Emperor (who was taking orders from MacArthur)? IOW, from the standpoint of what constitutional powers the US Federal government had, [edited] what was the status of an indefinitely occupied (but not ceded or annexed) foreign territory?
To be clear, the emperor was not deposed, although he did have to acknowledge publicly that he was not divine. His continued presence as head of state, if not head of the government, was a symbol of Japan’s continued existence as a sovereign state. It was under military occupation by the allied powers (mostly the US, with some help from Britain) but it was not owned by the allies or any individual other country.
The federal authority under which US forces operated in occupied Japan was entirely military, i.e. the physical occupation of a defeated enemy. Similar provisions operated in defeated Germany and Austria, although the details worked out differently, and the actual occupations were shorter.
The allied military in Japan were charged with keeping the peace, demilitarizing the country, helping the civilian population and economy recover from the effects of war, and helping to establish a stable, democratic government (and not so incidentally to keep them from becoming communist or coming under the influence of the Soviet Union). In the 20 months between the beginning of occupation and the adoption of the post-war constitution, the military were responsible for a lot of day-to-day government-like decisions, but they were still operating as a military force, not a civilian government. Once there was a legitimate civilian government, the role of the military took a step back from day-to-day governance to an oversight role. That role ended in 1952 with the Treaty of San Francisco.
My understanding is that Douglas MacArthur was the de facto head of government, operating in tandem with Emperor Hirohito, who continued on as head of state. What’s unclear to me is to what extent MacArthur was operating on his own vs. following Truman’s orders and policies. My guess is that, given MacArthur’s eventual firing by Truman for insubordination (yes, I know that was regarding the Korean War and not the reconstruction of Japan), MacArthur was probably running things as he saw fit rather than as a mere envoy or caretaker operating under orders from Washington.
The legal state of war between the United States and Japan did not end in September 1945, but rather in 1952 with the Treaty of San Francisco. For those 7 years, the United States ruled Japan as a military occupation of enemy territory during times of war. Military occupation was not a foreign concept in the 1940s or in the 1780s.
Okay, “state of war” covers a lot so that technically answers my question. Although calling it a “war” seven years after the shooting stopped sounds like a sophistry.
As stated in the Constitution of Japan, the Emperor is “the symbol of the State and of the unity of the people” and derives his position from “the will of the people with whom resides sovereign power.”