A common justification of the US dropping two nuclear bombs on Hiroshima and Nagasaki is that doing so caused a lesser loss of life. While the moral merit of this argument can be discussed, my question pertain to the validity of the premise that the Japanese would’ve been so stubborn, or patriotic, or fanatical that they essentially wouldn’t have given up.

How true is this claim? Is this more a result of orientalism and westerners ascribing these mystic mental faculties of loyalty to the Japanese, or is this based in evidence?

As an additional question, was this one of the actual motivations for dropping the bombs, or is this a later justification? Were the Americans belief in Japanese stubbornness well founded?