Six out of the eight nuclear weapons states have not ruled out first use of nuclear weapons. This document examines why states choose first use policies and the challenges involved in maintaining such a position.
States can be motivated to acquire nuclear weapons for both existential reasons and the pursuit of power. The six motivations for first use are: carrying out disarming first strikes, deterring conventional forces, compellence, extended deterrence, preventive strikes, and conquest.
The fundamental problem with first use is that it lacks credibility. This is because the path from first detonation to victory is either implausible or overly optimistic. Similarly threats of first use lack credibility because they are either disproportionate to the problem at hand or because the possibility of retaliation by the adversary can never be ruled out.
At the same time, first use policies fuel the spread of nuclear weapons and prompt existing nuclear weapons states to expand and upgrade their arsenals. The challenge of maintaining strategic stability is compounded by the rise of emerging technologies like hypersonic weapons, artificial intelligence, and counterspace systems, along with the ever-present threat of cyberattacks.
In short, first use policies bring few benefits while imposing high costs.TDD-Global-Nuclear-First-Use-GPM-AR-KK-2019-03