Map Description

Historical Map of World War II:

The Western Pacifc 1945

Illustrating:

Allied Invasions of Iwo Jima and Okinawa 1945

The Battle for Iwo Jima, February 19 - March 26, 1945

Operation ICEBERG was the Allied codename for the invasion of the Ryukyu Islands, especially Okinawa, in spring 1945.

The Battle for Iwo Jima, though a separate operation (Operation DETACHMENT), was a crucial part of the Allied island-hopping strategy to secure bases close to Japan for air raids and a potential invasion.

Iwo Jima (Operation Detachment)

• Dates: February 19 – March 26, 1945
• Allied Forces: U.S. Marine Corps (3rd, 4th, 5th Divisions), U.S. Navy, Army Air Forces
• Japanese Forces: ~21,000 under General Tadamichi Kuribayashi
• Strategy: Capture airfields for emergency bomber landings and fighter escorts. U.S. used massive amphibious assault; Japanese defenders used tunnels and bunkers to inflict heavy casualties.
• Outcome: Island captured after fierce fighting. U.S. suffered over 26,000 casualties (nearly 7,000 killed); almost all Japanese defenders killed or missing. Airfields proved vital for air operations.

Okinawa (Operation ICEBERG)

• Dates: April 1 – June 30, 1945
• Allied Forces: Over 180,000 (U.S. Tenth Army: Army and Marine divisions, supported by the largest Pacific naval fleet)
• Japanese Forces: ~100,000 under General Mitsuru Ushijima, plus Okinawan conscripts and civilians
• Strategy: Seize Okinawa as a base for invading Japan. Allies used joint air, land, and sea assault. Japanese withdrew to strong southern defenses and used kamikaze attacks against U.S. ships. Allies advanced slowly with combined arms tactics.
• Outcome: Okinawa secured after nearly three months. U.S. casualties over 49,000 (12,000+ killed); Japanese military losses over 100,000. Tens of thousands of Okinawan civilians died. Okinawa became a major Allied base for the final stage of the war.

Strategic Significance

• Operation ICEBERG was the largest amphibious assault in the Pacific and the last major battle of WWII.
• The campaign showed the high cost of invading Japan and influenced the decision to use atomic bombs instead of a direct invasion.

Summary Table

Battle	Dates	Allied Forces	Japanese Forces	Outcome/Significance
Iwo Jima	Feb 19 – Mar 26, 1945	USMC, Navy, Air Force	~21,000	Airfields captured; high casualties; vital for air ops
Okinawa	Apr 1 – Jun 30, 1945	Tenth Army, Navy	~100,000	Major base for Japan invasion; massive losses; influenced atomic bomb decision

Credits

Courtesy of the United States Military Academy Department of History.

Related Links

About World War II
WWII Timelines - February 19, 1945
WWII - Iwo Jima - Mount Suribachi