Honestly, I would take anything he says with a pretty serious grain of salt. He strikes me as a "I feed your confirmation bias gud" type of "historian.

His credentials are that he's a former high school social studies teacher.

From his patreon:

" I'm a former Social Studies teacher with two degrees; Social Studies Secondary Education, with a minor in Insect Biology, and Psychology. During the first degree, I focused on modern world history - so everything from World War 1 to present.  And for Psychology, my main focus was Cognitive Psychology, which is how the brain receives and processes information. "

https://www.patreon.com/knowingbetter

He's not completely suspect... but he's hardly a reliable source of information.

The back half of the video is more to the point. The post-war alliance structure is why Japanese atrocities were memory-holed. Once China fell to Communism, the Democracies in Asia (Japan, South Korea, Taiwan, Thailand and for 20 years or so, South Vietnam) formed a loose alliance against the Communist ones (China, North Korea, Indonesia until 1966 and eventually, Vietnam, Laos & Cambodia) with the aim of halting its spread. Japan's war crimes were understated or outright buried in order to keep them in the fold as Japan had invaded and occupied almost all of the Asian democracies before 1945. It'd have been a tough sell to say "These guys that butchered your people are now your allies. Treat them well." As far as the wartime Japanese government is concerned; most of them managed to actually survive the war so they were better able to defend themselves from legal maneuvers and power plays. Contrast this with Germany, where almost the entire senior Nazi command was killed or captured by 1945; and it so didn't help that the country was then divided with the Soviets. The cynics among us will likely argue that the Japanese officials were kept in power to prevent a descent into anarchy or slide towards Communism that would've resulted if the officials were executed. As far as the video itself is concerned, it's a fairly meticulous and thorough deconstruction of the topic. The only thing I have to add is that unlike Germany, the Soviets (with their vendettas and Communism that were pushed in East Germany) were locked out of reconstruction. For further reading on the topic, simply look into the immediate post-war reconstruction of Japan between September 2nd, 1945 (Surrender on the USS Missouri) to April 28th, 1952 (Treaty of San Francisco comes into force).