Which nuclear wars should worry us most?

Abstract

A nuclear exchange may have the potential to kill millions or billions of people, and possibly lead to human extinction.

In this post, I rank plausible nuclear exchange scenarios in terms of their potential to cause harm based on three factors: 1) The size of the involved countries’ nuclear arsenals; 2) The size of the involved countries’ populations; 3) The probability of the given nuclear exchange scenario.

Based on my rough prioritization, I expect the following nuclear exchange scenarios have the highest potential for harm:

Russia and the US India and Pakistan China and either the United States, India, or Russia

This is the first post in Rethink Priorities’ series on nuclear risks. In this post, I look into which plausible nuclear exchange scenarios should worry us most, ranking them based on their potential to cause harm. In the second post, I explore the make-up and survivability of the US and Russian nuclear arsenals. In the third post, I estimate the number of people that would die as a direct result of a nuclear exchange between NATO states and Russia. In the fourth post, I estimate the severity of the nuclear famine we might expect to result from a NATO-Russia nuclear war. In the fifth post, I get a rough sense of the probability of nuclear war by looking at historical evidence, the views of experts, and predictions made by forecasters. Future work will explore scenarios for India and Pakistan, scenarios for China, the contradictory research around nuclear winter, the impact of several nuclear arms control treaties, and the case for and against funding particular organizations working on reducing nuclear risks.