Why did Niels Bohr urge the Allies to inform the Soviet Union about the atomic bomb project?

Niels Bohr advocated for informing the Soviet Union about the atomic bomb project because he believed that the existence of such a weapon necessitated a new approach to international relations based on mutual confidence.1

Bohr argued that sharing this information was a critical first step toward preventing a postwar nuclear arms race. He championed the concept of an "open world" between nations, maintaining that transparency was essential for global stability. Despite his efforts to persuade leaders like Winston Churchill and Franklin D. Roosevelt, his proposals were rejected, and he was even unfairly suspected of espionage. Bohr continued to promote these principles of international cooperation and openness throughout his later life, including in an open letter to the United Nations in 1950.1