Fascinating, and more essential pieces of the puzzle that are typically left out of history books.
I'm guessing, however, that if they had been successful and had brought bubonic plague down upon the people of, say, Chicago, that we would still have self-hating, whiny apologists for Imperial Japan here on Free Republic who caterwaul about how America was just as bad or worse.
Thankfully there are still some thoughtful adults around, and may they multiply like rabbits :-)
There was a little problem with the public understanding of the Japanese intentions ~ their vast stores of jet planes, their development of high altitude bombers, their construction of giant aircraft carrying submarines, their atom bomb program, their bio-warfare program, etc. WAS KEPT SECRET until relatively recently.