With modern military emphasis on whiz-bang weapons technology and the constant quest for things that make a bigger bang on the battlefield, it's easy to forget that at the dark heart of war stands an infantryman and his individual weapons. Those who understand warfare from research or from personal experience generally realize this about the conflicts that have plagued mankind since the dawn of time.   Infantry weapons--often referred to as small arms--have fascinated soldiers and scholars for decades as they are the most personal aspects of combat. Small arms come into play when contact is close and potentially lethal. This was particularly true during the long, frustrating war in Vietnam, but much of the focus in studying that conflict has been either on aerial weapons--strike aircraft or armed helicopters--or on the originally much-maligned M16 rifle. There were huge numbers of other weapons used by both sides, but they are often ignored and rarely seen being used in combat action.   This book solves that problem. Divided into easily digestible sections and preceded by cogent discussions of each weapon type, the authors have presented an intriguing collection of photographs that depict the primary small (and not so small) infantry arms most common on Vietnam battlefields. There are rare and stirring images here that depict what it was like to fight in the jungle-covered mountains and in the rice paddies. Viewing these images is like studying a primer about one of America's longest and deadliest wars.