What aspect of the Cold War involved military rivalry?

The arms race between the two superpowers, namely the United States and the Soviet Union, is a crucial aspect of the Cold War that directly involved military rivalry. This competition was characterized by the accumulation and development of vast arsenals of nuclear weapons and other military capabilities. Each superpower sought to outdo the other in terms of firepower and strategic advantage, leading to significant advancements in military technology and a heightened sense of insecurity globally.

During this period, both nations invested heavily in their military programs, leading to a precarious balance of power known as mutually assured destruction (MAD), which suggested that a full-scale nuclear war would obliterate both belligerents. This rivalry dominated military strategy and foreign policy during the Cold War era and had far-reaching implications, influencing various events and conflicts around the world.

The other options, while relevant to the broader context of international relations during the Cold War, do not specifically encompass the military rivalry aspect. Trade agreements and sports competitions reflect diplomatic and cultural engagements rather than direct military competition, and the establishment of NATO was more about forming alliances for mutual defense than a direct aspect of the arms race itself.