Why didn't the US kill the Japanese emperor during the WW Two?

[Okay, maybe Mike Johnson is a competent parliamentarian.]

It's still that there's a sacral component to Japanese monarchy that just didn't exist in 20th century European monarchy.

Anyway, yes, this is the answer. And, indeed, this is the case for every remaining Far Eastern monarchy except maybe Cambodia; there's a reason why the example I gave above was Vajiralongkorn rather than a relatively-politically-potent European monarch like Felipe or Hans-Adam.

Speaking of the Cambodia monarchy, the infobox here is insane.
https://en.wikipedia.org/wiki/Norodom_Sihanouk

I believe Sihanouk holds the all-time record for number of different state/government leadership titles held.

[terkeypie]

I think it’s pretty simple, to avoid mass unrest, to avoid the Japanese surrendering to the USSR and then also to be able to maintain law and order during the occupation

[RINO Tom]

Quite relevant from a great channel:

https://www.youtube.com/watch?v=-6VRESxVT4w

[vitoNova]

Irrational fear of communism. 

[The Mikado]

Irrational fear of communism. 

The world ending up with only two extremely powerful nations after all other great powers were totally trashed was always going to lead to a massive competition for domination between the remaining ones. There was nothing "irrational" about American hostility to the Soviet Union, and frankly, the US would be hostile to Russia no matter what ideology or name it was going under at the time, communist or not, in that situation.

[Samof94]

Who made the decision not to kill him?

The Japanese.

It was one of their conditions of surrender that they keep their Emperor in power.

Remarkably, Japan fully recovered into a prosperous nation thanks in part to this negotiated peace deal.

Their work ethic is also an attribute of their global success.

Exactly. He’s more like the Pope than a typical European monarch.

[Amenhotep Bakari-Sellers]

As someone whom studied Buddhism, the goal was to not let Russia enter Japan, and the best way to end the war was a Treaty to allow Japan have their emperor but we give them our military.

Which they abided by since we bombed them with the Atom Bomb, time it was used

[America Needs a 13-6 Progressive SCOTUS]

Who made the decision not to kill him?

The Japanese.

It was one of their conditions of surrender that they keep their Emperor in power.

Remarkably, Japan fully recovered into a prosperous nation thanks in part to this negotiated peace deal.

Their work ethic is also an attribute of their global success.

Incorrect.
Once the US dropped the Atom Bombs on Japan, the Japanese were willing to accept just any terms of surrender whatsoever. If that included a requirement that the emperor be killed, that would have been no exception. It was the choice of the US to not insist upon it, and a shameful choice at that when you consider the implications that the US was essentially imposing an arbitrary death penalty by doing so.

[v0031]

I always believe this is my best post.

[Fuzzy Bear]

I wrote about this some time ago:

Most Americans, if asked to name the two (2) "dictators" that fought us in WWII, they would say "Hitler and Mussolini".  Mussolini was actually a rather secondary player in WWII; the other "dictator" that unleashed a sneak attack on our Navy at Pearl Harbor, the only direct attach on American soil since WWII by an actual country.  (I'm not minimizing 9/11, but that was something new and different.)  The leader who was responsible for that was Japanese Prime Minister Hideki Tojo, but it seems that few mention his name.  Nor do Americans, in general, consider Japan to be as evil as Nazi Germany (or the USSR, our war ally, for that matter), and it begs an explanation as to why this is so.

One reason is that Tojo was not Prime Minister for the entirety of WWII.  We date the beginning of WWII to September 1, 1939 when Hitler invaded Poland.  As a kid, watching history on documentaries, this seemed inaccurate.  Japan was one of the Axis Powers against us and they were fighting as early as July 20, 1937 in China.  The leader who started THAT war was Prime Minister Fuminaro Kenoe, whose name is virtually unknown to Americans now, and was fairly obscure back then.  Kenoe resigned in 1941 and committed suicide after Japan lost.  We don't date the beginning of WWII until 1939 because the writers of that history have been predominantly Euro-centric; and Asia-centric view of WWII would have reflected events differently. 

The reason Japan went to war was the same reason Germany went to war:  Living Space.  But the nations Germany annexed and attacked were nations with which Britain and/or France had War Guarantees with.  None of the Western Powers had any War Guarantees with either Japan or China (or Manchuria, which was an independent country once).  There were American citizens who were emotionally vested in what Germany did in Eastern Europe, but there was no such sympathy from Chinese-Americans that were relatively low in numbers and, sadly, whose views were pretty much not considered.   We made victory in Europe our first priority after Pearl Harbor, even though it was Japan, and not Germany, that attacked us. 

The atrocities committed by the Japanese were both civilian and military.  The military atrocities are well remembered by Americans, as there are many children of WWII vets still alive who heard the stories and were angered, but they were MILITARY atrocities.  Americans were, sadly, not as concerned about the atrocities in China by Japan as they were with the atrocities of Germany in Europe, and a good deal of that is racism.  And the atrocities, in general, were avenged by the Atomic Bombs on Hiroshima and Nagasaki.  There is a view that the accounts with Japan were settled with the Atomic Bomb whereas the accounts with the European Axis powers are unsettled to this day.

After the war, General MacArthur (the REAL one) pushed for, and got Emperor Hirohito spared from facing War Crimes charges.  The monarchy was preserved, but it was a Constitutional Monarchy where Hirohito was allowed to be a figurehead.  The hope was that Hirohito would encourage liberal democracy in Japan.  That part has worked out well.  But what happened with this was a conscious minimization of Hirohito's role in starting the hostilities.   Most Americans of my generation and the next generation were told pretty much that Hirohito was this weak individual, propped up by warlord politicians, who was something of a bystander to their warmaking.  This fiction was created to make the scheme go down well with Americans, but the fact is that Hirohito had an active role in many of the hostilities of Japan during those years.  Now that he's dead, more of Hirohito's actual role in the hostilities of WWII are becoming known.  Whether or not that's a good thing depends on how well people can handle the truth.

Today, Imperial Japan is a shell of what it once was.  After WWII, the people that paid the price were the Japanese MILITARY, not the Japanese MONARCHY.  The German Military got off much easier than the Japanese Military because Generals such as Erich von Manstein were able to convince people that the German military was not responsible for the atrocities of the Holocaust.  (This was another fable that may, or may not, have served us well.) 

Anyway, these factors are why I suspect that Imperial Japan has, however undeservedly, been able to be more "defensible" in the eyes of some.  It's because of how the history of the whole of WWII has been written and the whole of how deals were made to restructure Germany and Japan after their destruction.