On the basis of only this one article, it is my opinion that despite his literary accomplishments, Viet Nam twisted Journalist Gustav Hasford's psyche to such an extent that he may have lost all objectivity in his reporting.
If you want to read a truly remarkable account of what life in Viet Nam was all about, from the perspective of USMC combat infantrymen in the bush in Quang Tri Province, adjacent to the DMZ, find a copy of Karl Marlantes recently published MATTERHORN, a novel about Viet Nam recounting in the form of a novel, his personal experiences, not as a journalist, but as a combat infantryman and Platoon Leader. I can guarantee, you will have a hard time putting it down.
For more on Karls combat accomplishments, take a look at his Navy Cross Citation at http://militarytimes.com/citations-medals-awards/recipient.php?recipientid=4191 , or Google just his name.
Last week MATTERHORN was #7 on the NY Times list of best novels. I don't know where it is now. Some have ranked it right up there with RED BADGE OF COURAGE, MEMOIRS OF AN INFANTRY OFFICER, THE NAKED AND THE DEAD AND A FAREWELL TO ARMS.