Not a song I was aware of, but having looked at the lyrics it seems to be more of a post war reflection, and commentary on life for soldiers post War. It was released after the Paris Peace Accords/End of Draft, so the American withdrawal was underway.
We use the CCR track (1969) as part of the Anti War protest movement, and show how this affected and influenced political and public opinion.
The album, which I bought when it was released, would have been written and recorded a while before it was released in spring 1973. In any case there wasn't a lot of sense that the war was over then - Nixon had just got back into the White House by a landslide and the fighting was still going on which it did for another couple of years.