Moulton and Vance are both U.S. Marines. (There's "no such thing as a 'former' Marine.") "Pogue" is a well-established Army and Marine term for a rear-area person in a non-combat support position. "Pogues" are conceived of as comfortable, smug, arrogant, and incapable of fighting like real soldiers/marines. It is not complimentary.

Moulton led a platoon in battle in Iraq and was decorated for valor. Vance wrote articles and took photos as a journalist with the Marine Air Wing.

The Irish etymology makes a lot of sense. In recent years, the word has often been spelled "POG" and defined succinctly as "person other than grunt."