A key finding is that despite an overall decrease in the number of nuclear warheads in 2019, all nuclear weapon-possessing states continue to modernize their nuclear arsenals.

The nine nuclear-armed states—the United States, Russia, the United Kingdom, France, China, India, Pakistan, Israel and North Korea—together possessed an estimated 13,400 nuclear weapons at the start of 2020.

This is a decrease from the 13,865 nuclear weapons that SIPRI estimated these states possessed at the beginning of 2019.