On February 19, 1945 the USMC would land 30,000 marines on the island against a Japanese defensive force that numbered roughly 21,000 Japanese soldiers. Facing a Japanese commander who had learned valuable lessons from the losses on other Japanese islands, the USMC would eventually land over 70,000 marines and suffer over 25,000 casualties during the 36 day campaign. On February 19, 1945 the USMC would land 30,000 marines on the island against a Japanese defensive force that numbered roughly 21,000 Japanese soldiers. Facing a Japanese commander who had learned valuable lessons from the losses on other Japanese islands, the USMC would eventually land over 70,000 marines and suffer over 25,000 casualties during the 36 day campaign. Iwo Jima was the only island assault during the Pacific war that the attacking US forces would suffer worse casualties than the Japanese defenders.