It's 1945 and American forces are preparing to storm and hopefully take Iwo Jima, the small but heavily fortified Japanese island that will be crucial for Allied attempts to win the war in the Pacific. Turning down a promotion that might otherwise have removed him from harm's way, Sgt. Mike Strank (BARRY PEPPER) prepares and then leads his men into battle.
They include Native American Ira Hayes (ADAM BEACH), "runner" Rene Gagnon (JESSE BRADFORD), Hank Hansen (PAUL WALKER), Ralph "Iggy" Ignatowski (JAMIE BELL), Harlan Block (BENJAMIN WALKER) and Franklin Sousley (JOSEPH CROSS). Also accompanying them is John "Doc" Bradley (RYAN PHILLIPPE), a Navy corpsman present to tend to what might be a high injury rate.
Ambushed after believing the Navy bombardment had left all of the Japanese soldiers there dead, the American servicemen dig in, battle and eventually defeat the Japanese. When they ceremoniously raise an American flag at the top of Mount Suribachi, the image is captured by an AP photographer and soon travels back to the states where it reinvigorates public support for the war.
Realizing they have an opportunity to benefit from that, Treasury Department official Bud Gerber (JOHN SLATTERY) and military liaison Keyes Beach (JOHN BENJAMIN HICKEY) have the last surviving men who helped raise that flag -- Doc, Ira and Rene -- shipped back to the states. There, they're hailed as heroes by everyone as they travel around the country on a promotional tour designed to sell bonds for the war effort.
The men react differently to their newfound fame, with Doc being the most levelheaded, Rene enjoying the attention with his fame-seeking girlfriend Pauline (MELANIE LYNSKEY), and Ira turning ever more to booze to try to drown both the battle memories that still haunt him as well as the guilt of being labeled a hero when all he tried to do was survive.
Many years, later, Doc's adult son James Bradley (TOM McCARTHY) sets out to interview any surviving witnesses to help in writing a book about the men who fought in the Battle of Iwo Jima as well as the symbolic flag raising, both of which helped change the tide of the war effort.