Imagine we are living in the year 2030. New seismic activity indicates an underground nuclear explosion somewhere near the Arctic Circle. One more country announces it’s joining the once-exclusive club of nuclear weapons states that has now grown to 20 nations — more than double the number in 2020.

The trouble started in 2023, when a group of former allies of the United States renounced their adherence to the Nuclear Nonproliferation Treaty and opted to acquire the very nuclear weapons capabilities that they foreswore decades earlier.

Since then, nations across the world had raced to acquire the bomb, and the global security situation had become increasingly precarious. Sooner or later, as centers of nuclear decision making multiplied, one of those weapons was bound to go off, with consequences incalculable for all.

A far-fetched future? Perhaps. The nonproliferation treaty entered into force 50 years ago, on March 5, 1970. At the time, only five nations — the United States, the Soviet Union, China, Britain and France — were recognized as nuclear weapons states. Just four more countries — India, Israel, Pakistan and North Korea — have since acquired the bomb. And, yet, this scenario is more plausible now than many may think.

To understand why, we need to go back to 1963, when President John F. Kennedy warned of a “world in which 15 or 20 or 25 nations may have these weapons.” Kennedy expressed the widely held belief that further proliferation was likely, if not inevitable. Every nation that possessed the capability to build a bomb had done so and American officials worried that the trend was about to accelerate.