5 ms·

GP is talking about the bombs forestalling a possible Soviet invasion of Hokkaido. https://en.m.wikipedia.org/wiki/Proposed_Soviet_invasion_of_Hokkaido https:

• shakow 4y ago
  and I meant: “concerns were raised within the Soviet high command that an invasion of Hokkaido would be impractical and unlikely to succeed” Sure, there was a huge political part at play and I don't deny it, but even abstracting the US, purely militarily speaking, the Soviets would have been hard-pressed to succesfully invade Japan mainland.