China is accelerating the construction of its nuclear weapons, forcing the United States to more than double its previous estimates, the Pentagon’s intelligence service wrote in a report this week.

The Defense Intelligence Agency estimated that Beijing had about 200 nuclear warheads in 2020 and would reach at least twice that number by the end of the decade. Today, according to the DIA, China has already reached 500 such weapons and will possess more than 1,000 by 2030 – most of which could reach the United States.

“China is experiencing the most rapid expansion and most ambitious modernization of its nuclear forces in history,” the report states, while noting that Beijing’s arsenal is still far inferior to that of the United States or of Russia.

These figures appeared in the Pentagon’s annual report on China’s military strength released last year and are expected to be updated later this fall.

“Compared to the PLA’s nuclear modernization efforts a decade ago,” the document said, referring to the Chinese military, “current efforts dwarf previous attempts in scale and complexity.”

Despite detailed projections, the United States still does not understand why China has developed such a large arsenal and at such a rapid pace. Talks with senior Chinese military officials only resumed earlier this year, after a hiatus that began in 2022. U.S. defense officials have said their People’s Liberation Army counterparts were unwilling to discuss capacity building.

“We are seeing a very rapid expansion and modernization of the PLA’s nuclear forces, and they have not been transparent about the underlying intentions or objectives,” a senior U.S. defense official told a group of roving journalists, including Defense News, in June.

The official spoke after Defense Secretary Lloyd Austin met with his Chinese counterpart – the third in as many years. Austin raised the nuclear issue at that meeting, the official said.

The new DIA report says China’s pace stems from two broad goals: competition with the U.S. military and an effort to support old strategic plans with real capabilities — like a trainer who runs more advanced games with better players.

Among these concepts is the threat of limited nuclear use in a crisis involving “conventional” or non-nuclear weapons, the DIA said. Another solution is the development of smaller, or “low-yield,” nuclear warheads that could actually be used on the battlefield, rather than having deterrence value only.

The report said this second development suggests that “Chinese nuclear thinkers may reconsider their long-held view that nuclear war is out of control.”

For years, the Pentagon has said China’s military as a whole was growing rapidly as its leaders sought to build a “world-class” force, a euphemism for a force comparable to that of the United States. This goal includes a set of deadlines, linked to specific anniversaries of the Chinese Communist Party.

Most worrying for the Pentagon in recent times has been the year 2027 – the centenary of the People’s Liberation Army – when China’s leader told the military it should have the strength to invade Taiwan, a autonomous island that Beijing considers its legitimate territory.

U.S. officials who shared that assessment caution that this is not a deadline to actually invade.

Just as China is pouring resources into its Rocket Force, or nuclear wing, the service is being rocked by corruption problems. Several senior officers were sacked last year as part of a broader purge of military and defense officials.