"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.
Operation Ranch Hand happened in 1964.
Operation Arctic Fox happened on 1941-07-01.
Operation Days of Penitence happened on 2004-10-16.
Operation Acid Gambit happened on 1989-12-20.
It was operation Normandy
Cardinal Syn happened in 1998.
As far as we know, no St. Louis Cardinal player ever wore a "?".
Operation Deliverance happened in 1992.
Operation Protea happened in 1981.
Operation Bigamy happened in 1942.
Operation Anthropoid happened in 1942.
Operation Kitbag happened in 1941.
Operation Begonia happened in 1943.
Operation Kaika happened in 2006.
Operation Bristle happened in 1942.
Operation Bowery happened in 1942.
Operation Canuck happened in 1945.