At the tender age of twenty, Caputo enlists in the Marine Corps in the hopes to end his dreary days of comfortable living in a small, mid-western suburban town. He enters the war with romantic notions of being a hero, with thoughts of ending the war within a few short weeks or months and returning home to a parade of patriotic countrymen that will slap him on the back and ask him to tell them another heroic tale of his adventures in Vietnam. What he finds, however, is a rude awakening to the realities of a battle fought in the middle of the jungle with Viet Cong who refuse to play by the rules he has learned in his military training. In the thick of the jungle, Caputo learns the reality of war, while he comes to understand himself, as least as much as he comes to understand the enemy.

Philip Caputo was raised in the small prairie town of Westchester, Illinois, full of hot dogs, apple pies and ice cream. Yet, like countless other youth during this time, his strong desire to prove himself as a man, coupled with Kennedy's famous Inaugural Address to the nation, pulls him into the patriotic world of standing up for his country and defending its ideals with guns, if necessary.

During schooling at Loyola College, Caputo enlists with the Marines' ROTC program. At Basic Training, advanced training and Officer Basic School, Caputo learns much about Marine history, battle tactics and weaponry. However, what he really wants is just to get out there and have some adventure and, more than anything else, some experiences that will turn him into a man.

In January 1965, Caputo gets his chance. His first command as an officer begins with the men in Third Marine Division in Okinawa, Japan. Days there pass by uneventfully with the only sign of going into any battle being false alarms, delays, and frustrations. On March 7, 1965, however, three Companies, including Caputo's, are finally assigned to war. Boys and young men clamber onto planes with spirits full of adventure.

When first arriving in Danang, Vietnam, Caputo and his men step into what feels to them like just another military exercise. In a strict defensive operation, they stare at maps marked with grease pencils, patrol the borders of the military base, and dodge snipers each evening. They dig foxholes in the case of an attack and pile up one sandbag after another to protect them from enemy fire they never see.

Minor skirmishes come in slowly, much too slowly for Caputo and his men. They spend their days fighting mosquitoes rather than Viet Cong (VC), and their complacency slowly overtakes their excitement to be in the war. On April 22, another company is attacked by a band of VC. This trivial battle proves to be the turning point for Caputo and the others. After the excitement of the chase, the men finally get a chance to stage offensive attacks.

Amidst monsoon rains, biting insects, infectious diseases, random VC sniper fire, and eventually full out battles, the Marines charge into their romantic notions of war. They search villages full of hidden VC. They creep along passages laden with explosive mines trip wire, or ambushes. They hardly sleep, eat cold food, and slash through miles of jungle in the rain. With every step, they are running on a high that comes from staring down death, knowing at any moment, any of them could be shot by a sniper or blown to bits by a mine. This environment of high tension, however, comes at a price. Slowly, Caputo and his men begin showing signs of psychological trauma from the stress loads. Anger boils up from deep wells; they burn down villages and begin to hate.

At this point, Caputo is pulled off the firing line to receive training in Japan as an assistant adjutant before returning to headquarters back at Danang. During his stint as adjutant, he becomes more and more frustrated by rules that make sense on paper, but not to troops like his that are fighting in the jungle. He also gets to know death personally, as he takes on the duty of reporting casualties. In this job, Caputo sees death counts on both sides mount higher and higher. He comes to see all the lives that are being wrecked by the war. For the first time, he begins to question what America is doing in Vietnam.

Caputo's resentment to his comfortable office assignment grows stronger, when he learns that several men from his company have been killed. He succumbs to hallucinations, anxiety and depression, like many others around him. More than ever, Caputo wrestles with his mortality and with his desires to head back out there with "his men."

In November of 1966, Caputo is finally granted permission to return to line duty, where his men face constant tension without relief. In the conditions they have been living and fighting, Caputo crumbles within the first twenty-four hours, but manages to hold on to his sanity long enough to be granted a three day R&R a month later. Caputo considers deserting in Saigon, but after three days of rest, he finds himself waiting for a cargo plane, full of the dead, which will take him back to the lines and the men he knows he cannot desert.

Life on the front lines continues, and the men are tired, angry, depressed, hungry and wet. They have fought long enough and hard enough to see their romance of war vanish into the reality of it. Moments of temporary insanity increase, as they burn down a village of over two hundred Vietnamese civilians, laughing at the flames and the people whose lives they've destroyed.

The madness continues, when Caputo learns the location of two Viet Cong, who are in a nearby village. In a fit of borderline insanity, he orders their capture, and if necessary their execution, in retaliation for the lives of all the men lost in this battle.

Five months later, Caputo, along with one of his Marines, finds himself in front of a jury that is trying him for the murder of the two boys that were executed under his orders. Bewildered, Caputo searches his memory for the events that brought him there. He's been told to kill Vietnamese (VC or otherwise), and he kills. Now he is being tried for murder.

Caputo finds the trial hard to believe. Although eventually, he is found not guilty (of all but the misdemeanor of lying under oath), Caputo has a lot of time to come to understand the cover-ups the military is making with war. Shortly thereafter, Caputo is released on honorable discharges. By this point Caputo and his men have fought long enough to see their hard work amount to nothing, and most, if not all of them, just want to go home. In 1967 he leaves Vietnam.

Caputo returns to Vietnam ten years later as a field correspondent for the Chicago Tribune to report on the final moments of the war before Saigon is overrun by the North Vietnamese. In the impending confusion and fear that encompasses thousands of people trying to evacuate by land, sea or air, Caputo comes full circle with his feelings on the war. Once safe upon a helicopter assault ship in the South China Sea, Caputo and many others are left to feel the weight of the end of a decade of war.