The most destructive military tool ever developed by humans. Mass use of nuclear weapons is the only way we can erase human civilisation from the face of the Earth within a couple of minutes. Luckily, so far, the only available proof of that remains the fate of Hiroshima and Nagasaki. On the other hand, nuclear weapons helped to keep the Cold War from turning into a violent conflict between the USA and the USSR to a large extent. This is because nuclear weapons greatly amplified the difference between the power to hurt and the power to defeat the enemy. Nuclear deterrence has been based on this distinction ever since. In other words, if you have the capability to destroy your opponentʼs population centres with your nuclear weapons, no country would dare to attack you in the first place.