Which external rivalry led to the largest military engagements?

The external rivalry that led to the largest military engagements was between the Allies and the Axis during World War II.

World War II, which lasted from 1939 to 1945, was a global conflict that involved over 30 countries and resulted in the largest military engagements in history. The main rivalry was between the Allies, primarily composed of the United States, the Soviet Union, the United Kingdom, and China, and the Axis, led by Germany, Italy, and Japan. This rivalry was characterised by a series of large-scale military engagements, including the Battle of Stalingrad, the Battle of Midway, and the Normandy Invasion.

The Battle of Stalingrad, fought between August 1942 and February 1943, was one of the largest and deadliest battles in history. It involved over two million military personnel from the Soviet Union and Germany. The battle resulted in heavy casualties on both sides and marked a turning point in the war in favour of the Allies.

The Battle of Midway, which took place in June 1942, was a decisive naval battle in the Pacific Theatre. It involved the United States and Japan and was one of the largest naval battles in history. The United States' victory at Midway marked a significant turning point in the Pacific War.

The Normandy Invasion, also known as D-Day, was the largest amphibious invasion in history. It took place on 6 June 1944 and involved over 156,000 Allied troops. The successful invasion marked the beginning of the end for Germany's control over Western Europe.

These military engagements were a result of the intense rivalry between the Allies and the Axis. The scale and intensity of these battles reflect the global nature of World War II and the high stakes involved in the conflict. The rivalry was driven by ideological differences, territorial ambitions, and the desire for global dominance, leading to the largest military engagements in history.