A Stockholm-based watchdog says the world's nine nuclear-armed states continue to modernize their nuclear weapons as the countries deepened their reliance on nuclear deterrence in 2023. The Stockholm International Peace Research Institute estimated Monday that some 2,100 of the deployed warheads were kept in a state of high operational alert on ballistic missiles and nearly all belong to Russia or the United States. For the first time, China is also believed to have some warheads on high operational alert. In a separate report, the International Campaign to Abolish Nuclear Weapons said the nine countries spent a combined $91.4 billion on their arsenals last year.
