MOT 1945: BATTLE OF IWO JIMA: UNITED STATES MOBILIZING

In mid-February, the Marines prepared for an assault near enemy waters, where surprise was no longer an option. They were thoroughly briefed on the enemy's formidable defenses, described as a fortress on the Pacific Ocean, ensuring they knew what to expect.

What was said about the enemy's position in relation to the Pacific Ocean?

What did the Marines know about the enemy's defenses before the assault?