Operation Downfall did never start.

But the first scheduled invasion against the southen Japanese island, codename "olympic" and was to start on nov 1 1945.

Operational Downfall, or the American invasion of the Japanese home islands was planned sometime during October of 1945. The operation became moot after the total capitulation of Japan after the nuclear strikes on Hiroshima and Nagasaki.

The US would have invaded Japan on 01 Nov 45 Operation: DOWNFALL.

"Operation Cardinal" happened. The details of an OSS operation in Mukden, Manchuria, shortly after the surrender of Japan is detailed in an article by Peter Clemens entitled, "Operation Cardinal: The OSS in Manchuria, August 1945."

It was published in a journal called Intelligence and National Security (Vol. 13, No. , Winter 1998)

Hal Leith, the Russian/Chinese linguist on the mission, is alive and well.

I think the questioner is confusing Operation Cardinal with Operation Downfall which was planned for (I believe) November 1945. After the two atomic bombs were dropped on Hiroshima and Nagasaki, and the surrender of Japan less than a week later, Operation Downfall became unnecessary.

There was a downfall.

It was King Peter's downfall.

The downfall of the city.

The market experienced a downfall.