Answer:
To provide first-hand knowledge of past events from a participant.
Step-by-step explanation:
In Mandatory Military Service in America, the author includes the recollections of a Vietnam veteran in paragraph 8 in counterpoint. Most likely, the purpose of doing so is to provide first-hand knowledge of past events from a participant. The veteran presented participated in the Vietnam War. This means that he has experienced war first-hand. This leads him to have a type of knowledge that other people do not have, and that could prove important to the analysis the author is trying to make.