I never, ever heard of it? And I've spent some time reading up on American armed forces history. I checked Wiki and its blurb wasn't all that big. Anyhow, read the brief release @ http://www.hoover.org/library-and-archives/acquisitions/178936
yup as did canada uk, australia, france and a number of other countries....it wasnt for no reason the communists saw the western nations as hostile for decades, we attacked them....it was really ironic for the usa and france, two nations born in revolution against monarchy fighting a movement trying to overthrow a monarchy...
They were there to rescue the trapped Czechoslovakia troops trapped in a pocket between boshlevik and green armies. - - - Updated - - - Its hardly ironic - - - Updated - - - It would be ironic if they had fought to keep a monarch in power.
They weren't deployed against the revolution. They were there to help the Czechs get to the Western Front.