Despite nuclear deterrence, the risk of a terrorist or rogue actor obtaining nuclear weapons remains real. Some researchers have suggested that even a single nuclear attack, such as a dirty bomb, could kill millions of people. This would violate international humanitarian law, which aims to protect civilians and their property from indiscriminate attacks, as well as rules that prohibit weapons of mass destruction and the use of weapons that cause unnecessary suffering.
Since the first two nuclear attacks, on Hiroshima and Naga, scientists have gathered much more knowledge about the effects of nuclear weapons. A modern nuclear exchange between NATO and Russia, or between the United States and China, would create a global catastrophe beyond anything experienced so far.
An all-out nuclear war would kill most of the world’s population, as well as destroy cities and other industrial areas. Many survivors outside the area of total destruction would suffer severe burns, blindness, or internal injuries and die from exposure to radiation. In addition, water supplies, power plants, and hospitals would be destroyed and emergency services would be overwhelmed.
A limited nuclear attack, in which only a small number of ICBMs are launched, would be much less devastating but still kill millions of people from blast and local radiation. It also might deprive people of food, as agricultural infrastructure would be destroyed. Many nuclear planners have considered such an attack, in which the objective is to cripple the enemy’s ability to retaliate by destroying key military targets like bomber bases, submarine support facilities, and missile silos.