People pretend that televised tragedies are real when they use actors and etc, is because these tragedies can easily happen. For example a kidnappers kidnaps a child from a park, a unsupervised child can easily walk away because the parent is on their phone texting or scrolling on instagram. Basically the producers want to make awareness that the society should try to prevent these "Fake Tragedies" from happening.
It was the "never surrender" mentality of the Japanese army. The thought was of dealing with a million or 2 million US lives to invade Japan. The use of the atomic weapon was to save lives.
