Which three battles are known as the three crosses of war in World War I?

The correct answer consists of three significant battles that highlight crucial moments in World War I, often referred to collectively in historical contexts concerning the contributions of the U.S. Marine Corps. Belleau Wood, Mont Blanc, and Soissons were pivotal in demonstrating the effectiveness and bravery of U.S. forces during the war.

Belleau Wood, fought in June 1918, was a defining battle for the Marine Corps, where they exhibited remarkable resilience and fighting spirit against German forces, earning them a reputation that endures to this day. Mont Blanc, although not as widely discussed, involved operations that were key in the broader context of the war, contributing to the fight in the region. The battle of Soissons, occurring in July 1918, followed Belleau Wood and was part of the larger Second Battle of the Marne, showcasing additional American tactical and strategic capabilities.

This selection of battles underscores the unique and impactful role played by the Marines in World War I and the evolution of modern warfare, marking significant turning points on the Western Front. The other options include battles that, while important, do not specifically form this recognized grouping associated with the U.S. Marine Corps.