Fully illustrated, this book assesses the US Marines and Japanese troops fighting in three bloody battles of World War II in the Pacific. In June 1944, the United States military launched an offensive against the Japanese forces holding the Mariana Islands and Palau. The US Marine Corps played a vital role in this campaign alongside Army and Navy forces, while their Japanese opponents mounted a desperate defense of their conquests amid the harsh island terrain. This book assesses both sides' doctrine, tactics, weapons, and battlefield effectiveness in three battles of this stage of the Pacific War. Landing on Saipan on June 15, the Marines established a beachhead as the Japanese defenders strove to fight to the last man. On July 21, US Marine Corps and Army forces landed on Guam. Only on August 10 was Guam declared secure by the Americans, and even then resistance continued. US forces landed on Tinian on July 24 and wrested the island from its conquerors. Alongside Army troops, the US Marine Corps also targeted the island of Peleliu. Predicted to last four days, the US assault on Peleliu lasted more than two months as the defenders inflicted appalling US casualties. Featuring all-new artwork and mapping alongside archive photographs, this study assesses the tactics and technology employed by the Marines and their Japanese opponents in these bloody battles, as the Pacific War moved toward its grim climax.