Hiroshima atomic bombing launches nuclear age and reshapes global deterrence

On 6 August 1945 the United States aircraft Enola Gay released the uranium‑fueled bomb “Little Boy” over Hiroshima, Japan. The explosion killed an estimated 80,000 people instantly, flattened much of the city and marked the first use of nuclear weapons in war.

The devastation ushered in the nuclear age, leading to a Cold‑War system of mutual assured destruction that restrained direct super‑power conflict. Over the ensuing decades, arms‑control treaties limited strategic arsenals, but many of those agreements have now lapsed. The United States, Russia and China are simultaneously modernising their nuclear forces, ending the bipolar deterrence structure and creating a new tripolar strategic environment.

Analysts warn that the erosion of the post‑Cold‑War nuclear architecture raises the risk of unchecked competition and lowers the barriers that previously helped prevent nuclear war.