It is not by the Tomb of he Unknowns at Arlington. The curved shape makes the WW II memorial a possibility but it somehow looks like it predates that structure, so I am honestly at a loss about where the photo was taken.
I would confidently bet that the old trooper is a member of America's Greatest Generation. Back in 1941 many of them signed up and told their wives or girl friends, "Goodbye dear, I'll be back in a year."