New Report Reveals Nuclear-Armed States are Expanding and Upgrading Their Arsenals
״We are in an era of expanding nuclear arsenals, intensifying nuclear rhetoric, and the abandonment of arms control agreements,” said Hans M. Kristensen, Senior Fellow in SIPRI’s Weapons of Mass Destruction Program
Successful launch of Sarmat ICBM held at Plesetsk Cosmodrome, Wikipedia
Nearly all nine nuclear-armed states — the United States, Russia, the United Kingdom, France, China, India, Pakistan, North Korea, and Israel — continued in 2024 with intensive programs to modernize their nuclear arsenals. These programs include upgrading existing weapons and adding new versions to their stockpiles.
According to a report by the Stockholm International Peace Research Institute (SIPRI), as of January 2025, the global nuclear weapons inventory stood at approximately 12,241 warheads. Of these, about 9,614 were available for military use. Around 3,912 warheads were mounted on missiles and aircraft, while the rest were stored in central depots. Approximately 2,100 of the deployed warheads were on high operational alert — the majority belonging to the U.S. and Russia, although there are indications that China may have started placing some warheads on missiles during peacetime.
Since the end of the Cold War, the dismantling of retired warheads in the U.S. and Russia has consistently outpaced the deployment of new ones, leading to an overall annual decrease in the global nuclear stockpile. However, this trend may soon reverse due to a sharp slowdown in dismantlement rates, alongside an acceleration in the deployment of new weapons.
“The era of reducing nuclear arsenals that began at the end of the Cold War is coming to an end,” said Hans M. Kristensen, Senior Fellow in the Weapons of Mass Destruction Program at SIPRI and Director of the Nuclear Information Project at the Federation of American Scientists (FAS). According to him, we are entering a period of expanding arsenals, intensified nuclear rhetoric, and abandonment of arms control agreements.
Russia and the United States together hold about 90% of the world’s nuclear weapons. Their stockpile sizes remained relatively stable in 2024, but both are advancing extensive modernization programs that may increase the size and variety of their arsenals in the future. Unless a new arms control agreement is reached, the number of deployed warheads is expected to rise after the expiration of the New START treaty in February 2026.
The U.S. nuclear modernization program faces budgetary and planning challenges that could delay and inflate the cost of its new strategic arsenal. In addition, the development of new tactical nuclear weapons adds further strain to the system.
Russia is grappling with similar issues, including another failed test of the “Sarmat” intercontinental ballistic missile and delays in upgrading other systems. Nonetheless, both countries are expected to increase their nuclear capabilities as a result of intensive modernization efforts and in response to similar developments in China.