This powerful film, like the book on which it is based, puts forth a message against the Vietnam War specifically and against war in general. Like Wilfred Owen and Erich Maria Remarque generations earlier, Ron Kovic shows the idealism of youth corrupted by the flag-waving propaganda of wartime. In the early 1960s, many in the US were fixated on the idea that the Communists were going to "take over the world." The argument was that if Communist aggression took place even halfway around the globe, it was a threat to the US, and US soldiers had to fight these remote wars in countries such as Vietnam where the internal situation was little understood by the hawkish American policymakers. The film shows the pointlessness of American involvement in Vietnam, where there is no clear enemy and where the civilian population ends up victimized, like the American soldier who is fighting for a lost cause.

Kovic (Tom Cruise) is shown as a naive youth encouraged by his religious mother to enlist because it is "God's will" that he join the fight against Communism. Despite doubts expressed by his friends and his father, Kovic is undeterred. In Vietnam, he eventually finds himself in a totally different situation from the glorious one he had imagined. He accidentally kills one of his own men in a friendly-fire incident. His platoon massacres innocent civilians, thinking the enemy is hiding in their village. Kovic is then wounded and paralyzed from the waist down for life.

In the VA hospital stateside for his recovery, Kovic finds the doctors and the staff unsympathetic. Conditions are unsanitary and overcrowded. Kovic breaks his paralyzed leg in a futile attempt to walk again, and he must remain immobilized for months while it heals in order to avoid having it amputated. The hospital lacks proper equipment and resources.

When he returns home in a wheelchair, even his own family, apart from his father, seem remote. At first, he continues to argue that the war is justified, but he finds that his brother, sister, and even mother do not support him. The country as a whole is indifferent or hostile. Eventually, he realizes the war has accomplished nothing and that his own life has been ruined for no reason. He has sacrificed himself, but now there is no one to appreciate him or to care about his plight. Only when he meets with other veterans at a retreat in Mexico does he develop an articulate antiwar viewpoint and become an activist against the war. Altogether, the point of the story is that the Vietnam war accomplished nothing and victimized a generation of innocent youths who bought the government line about it.