Hi
When was Japan legally defeated 1945 or with the signing of the San Francisco Peace Treaty?
I look forward to your feedback
My understanding is that Japan admitted defeat with its formal surrender. it was subsequently occupied, just as Germany had been after the war. Legal defeat came with its formal surrender. Correct?
The Pacific war came to an end on August 14 (August 15 in Japan). The formal surrender was signed on September 2 in Tokyo Bay aboard the battleship USS Missouri.
Allied occupation of Japan
From 1945 to 1952 Japan was under Allied military occupation, headed by the Supreme Commander for Allied Powers (SCAP), a position held by U.S. General Douglas MacArthur until 1951. Although nominally directed by a multinational Far Eastern Commission in Washington, D.C., and an Allied Council in Tokyo—which included the United States, the Soviet Union, China, and the Commonwealth countries—the occupation was almost entirely an American affair
Defeat leads to surrender.
Conciliation leads to treaty.
According to a Wikipedia article, the San Francisco Treaty ended the occupation of Japan:
“This treaty served to officially end Japan’s position as an imperial power, to allocate compensation to Allied civilians and former prisoners of war who had suffered Japanese war crimes during World War II, and to end the Allied post-war occupation of Japan and return sovereignty to that nation.”
I’d say Japan was defeated in 1945 when they formally agreed to surrender to the United Nations. Then they learned what the full terms of that defeat would be in 1951 (or 1956 or never depending on how you view the situation with Russia).
Is “defeated” a legal term?
If it means “When did Japan finally stop fighting?”, there’s a basis to say December 1974.
A person does not represent a government. The government officially admitted defeat on board the USS Missouri in Tokyo Bay.
When did Japan withdraw from occupied territory?
They ruled Korea for decades before the war. Lost it afterwards.
Hong Kong, Burma, and parts of China were all occupied Japanese territory. I’m not sure when Japan surrendered there.
Burma’s war history is messy. No exact date when Japan completely pulled out.
I was trying to make the point that it took some time for all mobilized Japanese troops to lay down their weapons.
Disengaging isn’t easy when you’re being attacked. 
Burma had rebel troops. China did too, the Nationalists and the Communists. Japan was fighting on multiple fronts. Everybody has to agree before the fighting can stop. Then the Japanese troops had to withdraw and return home.
I think the OP’s question is better formed this way:
The United States declared war upon Japan on Dec. 8, 1941. That state of war ended at what point?
a) The Surrender?
b) The Formal Surrender?
c) The Treaty of San Francisco?
Or another way to put it is "Define ‘legally’ "
As to the effect of the December 8, 1941 declaration of war against Japan, the declaration was rescinded following the peace treaty with Japan, which entered into force on April 28, 1952.
In case someone is curious, the declaration of war against Germany was terminated by an act of Congress, signed by the President on October 19, 1951. The other declarations of war against Italy, Bulgaria, Hungary, and Rumania were terminated by different peace treaties, all of which entered force on September 15, 1947.
ETA: also note that in the US, the ratification of a peace treaty does not occur upon signing, but after submission and approval by the Senate.
There are other measures to when the “war ended,” however. If my memory serves, for the purposes of awarding veterans benefits in the US, the end date for WWII was counted as December 31, 1946.
it’s not unknown for different days to be appointed for different purposes. The British passed a Termination Of The Present War (Definition) Act in Nov 1918 to achieve this. Many men had been conscripted ‘for the duration’ - how do you reckon that when the war has not formally ended?
Not really, no. “Defeat” is more of a military concept. A comabatant is defeated when they are unable to offer further resistance, or when they feel constrained to stop offerign resistance.
By what law?
There is no real ‘international law’ – only agreements between countries, which they can choose to break.
Laws are passed by each country, and apply to their own territory that they control. Countries don’t usually expect to lose a war, so they don’t preemptively pass laws defining legally just when they are ‘defeated’. For example, I can’t think of any USA law defining legally a defeat in a war. I guess that’s why they have to negotiate a peace treaty at the end of each war.
That would be so if America was the only country fighting.
Indeed. Japan declared war on the US and the British Empire in the one declaration. Furthermore, Japan was at war on France and Portugal after invading their empires.
Rather a few members of the empires in Indochina might feel slightly aggrieved that they were forgotten. It was not exactly a good time.
Declaration of war does have a long history of specific legal meaning, and a slew of international law and treaties involved in its use. The 1907 Hague Convention on the opening of hostilities being the pertinent one. A specific value of such declarations may include that the Geneva convention comes into force (not that Japan took any notice.) However the convention doesn’t require a formal declaration, attacking another country is clearly a declaration as well.
As WWII progressed a very large fraction of the world formally declared war on the Axis Powers, which of course meant Japan as well. By the end of the war Japan was formally at war with most of the planet.
In terms of defeat, I think it is reasonable to look to the date of surrender. Up until then Japan had been hoping for a negotiated end - in which they could maintain their hold on at least a goodly portion of the territories they had taken. It seems that most people agree that the sudden termination of the treaty with Russia and the threat of Russian invasion to their north made up their minds that they had no choice but to call an immediate halt to the war on the terms dictated by the US - unconditional surrender. That declaration to the UN meant that Japan was offering surrender not just to the US, but to most of the countries in the world, which at the time were formally, legally, at war with her.
But, given Japan was given over to occupation, there wasn’t a simple end to hostilities. Whether you count the occupation as a continuation of “war” or not probably depends upon your point of view. Nobody was fighting anymore.
Thank you Francis Vaughan. So “Declaration of war does have a long history of specific legal meaning” but “defeat” is not a legal term as UDS pointed out upthread “Defeat” is more of a military concept." Having read up on international laws dealing with war (the Charter of the UN) I wrongly assumed that ‘defeat’ had a legal interpretation in international law as well.
“Whether you count the occupation as a continuation of “war” or not probably depends upon your point of view.” Are there any respected historians who count the occupation of Japan as being a “a continuation of the war”?
This is all factually untrue. International law, both through treaties and through customary international law, is universally recognized. Unfortunately, there is a frequently expressed opinion that international law does not exist because there is no ultimate authority that presides above sovereign states, sort of how a court system presides with authority to punish criminal acts or find equity in civil matters.
International law does not function in the same way, but that does not mean it does not exist. Insisting that international law does not exist because it doesn’t work the same way that other laws work is sort of like saying that bonds are not investments because they don’t work like stocks; like bikes aren’t transportation because they don’t work like cars; like birds aren’t pets because they don’t act like dogs.
Finally, I quote the Supreme Court if you still labor under the mistaken impression that international law does not exist: “International law is part of our law, and must be ascertained and administered by the courts of justice of appropriate jurisdiction as often as questions of right depending upon it are duly presented for their determination. For this purpose, where there is no treaty and no controlling executive or legislative act or judicial decision, resort must be had to the customs and usages of civilized nations, and, as evidence of these, to the works of jurists and commentators, not for the speculations of their authors concerning what the law ought to be, but for trustworthy evidence of what the law really is.”