Now the popular portrayal of WWII seems kind of idealistic, but there's plenty of historical evidence to suggest many Allied troops really did not want to be there, and the scale of desertion [1] was quite high - In addition to corruption, mismanagement, and racketeering [2]. I only really considered this after encountering "Deserter: The Last Untold Story of the Second World War" by Charles Glass in a used bookstore…
And Joseph Heller was a veteran of WW II. The NY Times Magazine's issue for the 50th anniversary of VJ day included an essay by him. Some reservists were called back for Korea, but was he one of them?
[Edit: added qualified military system with "US".]