At the end of the day, 4/5 is probably a star higher than the book actually deserves. However, given the unique perspective that the book takes, along with the interesting facts and tidbits sprinkled throughout, I ended up enjoying the read despite its apparent flaws.
In GRUNTS, Longley tries to replicate the experience of the soldier of Vietnam, starting from the nervous and naive recruit at boot camp and ending with the mangled sufferer of PTSD trying to integrate back into society. Attention isn’t paid to specific years or hard dates, instead opting to explain the soldier's lookout and challenges gradually throughout all five chapters. From poor training to hard drug and alcohol problems, the Vietnam War is painted as a vivid emotional hell. In addition, significant attention is to paid to under-recognized racial issues that existed before, during, and after the war for many POC veterans.
Despite drawing on a vast wealth of testimony from veterans and records of deceased soldiers, only the basics of the war itself is described. Outside of the Tet Offensive, the My Lai massacre, and some actions of the anti-war movement, it's very difficult to pin-point when shifts in military outlooks changed for the young men serving in the far-off country. Specific military and political operations and procedures are often left hinted at rather than thoroughly explained to the reader. But then again, how many of soldiers were even acutely aware of the higher up's decisions and their implications to begin with?
While I wouldn't call the stories Longley relates to the reader as "generic," as some other reviews have, it ultimately doesn't say anything particularly new about Vietnam, either. Even so, it's a solid introduction to some of the controversies of the Vietnam War, especially if paired with another book on the timeline of said war.