The Stockholm International Peace Research Institute (SIPRI) has released its annual assessment, the SIPRI Yearbook 2025, revealing a significant expansion of China's nuclear arsenal. The report indicates that China is adding approximately 100 nuclear warheads to its stockpile each year, a rate faster than any other country. This rapid growth has propelled China's total warhead count to an estimated 600 by early 2025, a substantial increase from 410 in 2023.

This expansion occurs against a backdrop of overall global nuclear weapon reductions, primarily due to the United States and Russia dismantling older systems. However, SIPRI's findings suggest that this trend is coming to an end, with a "dangerous new nuclear arms race" emerging amidst weakening arms control frameworks. While the total global inventory of nuclear warheads decreased from 12,405 in 2024 to 12,241 in January 2025, the number of warheads in military stockpiles has increased, signaling a shift towards modernization and deployment of new nuclear systems.

According to the SIPRI report, China has been rapidly constructing approximately 350 new intercontinental ballistic missile (ICBM) silos across three desert regions in the north and three mountainous areas in the east. This infrastructure development suggests that China could potentially match the ICBM counts of Russia or the United States by the end of the decade, depending on how it structures its forces. If China fills these silos with single-warhead missiles, it could deploy around 650 warheads on ICBMs within a decade. However, if each silo were filled with a missile equipped with three MIRVs (multiple independently targetable re-entry vehicles), this number could rise to over 1,200 warheads.

Despite this rapid buildup, China's nuclear arsenal remains smaller than those of Russia and the United States, which together possess around 90% of the world's nuclear weapons. Russia holds the largest arsenal with 5,459 warheads, while the US possesses 5,177. However, SIPRI Director Dan Smith notes a concerning trend of "everybody moving in that direction of upgrading," including established nuclear powers and relatively new ones like North Korea, Pakistan, and India.

China maintains that its nuclear strategy is purely defensive. Foreign Ministry spokesperson Guo Jiakun stated that China keeps its nuclear capabilities at the minimum level required for national security and adheres to a policy of "no first use" of nuclear weapons. China is the only nuclear-weapon state to have adopted such a policy, committing to not use or threaten to use nuclear weapons against non-nuclear weapon states.

Hans Kristensen, an associate senior fellow at SIPRI, suggests several factors behind China's rapid warhead buildup. These include President Xi Jinping's ambition for China to become a world-class military power by mid-century, a reassessment of the adequacy of its previous minimum deterrent, and concerns that increasingly capable US missile defense systems could reduce the effectiveness of China's retaliatory capabilities.

The SIPRI report highlights that nearly all nine nuclear-armed states – the United States, Russia, the United Kingdom, France, China, India, Pakistan, North Korea, and Israel – are actively modernizing their nuclear arsenals. This includes upgrading existing weapons and adding newer versions. While most warheads are stored separately from their launchers, China may now be deploying a small number on missiles during peacetime, similar to the practices of the United States and Russia.

The expansion of nuclear capabilities among multiple states raises concerns about a potential "rapid increase in deployed warheads" and the ability of nuclear-armed states, particularly China, to "threaten the destruction of significantly more targets." As the world becomes increasingly unstable, the likelihood of nuclear weapons being used is also increasing, underscoring the urgency of addressing the emerging nuclear arms race.