A tough sergeant trains and leads a squad of marines against Japanese-held islands in the Pacific.
Corporal Robert Dunne (Arthur Franz) narrates that he is with Marines in New Zealand. Sergeant John Stryker (John Wayne) tells his rifle squad that he will teach them how to fight. Al Thomas (Forrest Tucker) does not like Stryker, but Charlie Bass (James Brown) says Stryker is fair.
Stryker tells Peter Conway (John Agar) he served under his father before he was killed at Guadalcanal. Stryker trains the men and injures Choynski (Hal Baylor) showing him how to use a bayonet. Conway complains that Stryker is too strict.
While on liberty Conway dances with Allison (Adele Mara) and kisses her. Stryker is drunk, and his men help him. Conway gets a ride with Stryker, argues about his father, and visits Allison. They both want to marry, but after the wedding they have only 44 hours together.
The men ship out. After naval and air bombardment they attack an island. Some are killed on the beach. Stryker tells his men to wait. They are ordered to take a Japanese machine-gun bunker and do so with casualties. Thomas goes to get more ammunition and accepts coffee from a mortar squad. Japanese bayonet the two men waiting.
At night Stryker's squad has to hold the line without moving. They hear wounded Bass calling his name, but Stryker won't let Conway go after him. On the fourth day the island is secured.
On a ship Stryker tells Dunne to give the men sake. Young Mike McHugh (Martin Milner) and two others join the squad. Bass returns and tells Stryker that Thomas did not bring the ammo. Stryker has a fist fight with Thomas until an officer stops them. Thomas covers for Stryker and admits he was wrong to stop for coffee.
Conway gets a letter from Allison that he has a son. The men get ten days in Honolulu. Drinking Stryker meets Mary (Julie Bishop) and goes to her place. She has a baby, and he gives her money. Stryker tells Bass not to worry about him. Conway tells Stryker he does not like him. During grenade practice Stryker saves Conway's life.
Iwo Jima has 20,000 Japanese. The squad gets out of landing vehicles on the beach. Stryker's squad is ordered to move out. Frank Flynn (Richard Jaeckel) is wounded, and his brother Eddie Flynn (Bill Murphy) carries him. Regazzi (Wally Cassell) goes to get a bazooka and comes back with a tank that destroys a pillbox with a flamethrower.
For three days they do not advance. Conway and Stryker are reconciled as Conway admits he was out of line. They climb a mountain. Stryker is given an American flag to put on top, but he is shot dead. Thomas reads a letter by Stryker to his son, and Conway says he will finish the letter for him. They raise the flag, and Conway leads the men into battle.
This realistic war drama contains actual combat footage
and shows the violence of "trading real estate for men"
in war. The sensitive Conway comes to respect the tough sergeant,
who warns his son in a letter that much of what he had done was