WASHINGTON — After decades of maintaining a minimal nuclear force,China has re-engineered many of its long-range ballistic missiles to carry multiple warheads, a step that federal officials and policy analysts say appears designed to give pause to the United States as it prepares to deploy more robust missile defenses in the Pacific.
What makes China’s decision particularly notable is that the technology of miniaturizing warheads and putting three or more atop a single missile has been in Chinese hands for decades. But a succession of Chinese leaders deliberately let it sit unused; they were not interested in getting into the kind of arms race that characterized the Cold War nuclear competition between the United States and the Soviet Union.
Now, however, President Xi Jinping appears to have altered course, at the same moment that he is building military airfields on disputed islands in the South China Sea, declaring exclusive Chinese “air defense identification zones,” sending Chinese submarines through the Persian Gulf for the first time and creating a powerful new arsenal of cyberweapons.
Many of those steps have taken American officials by surprise and have become evidence of the challenge the Obama administration faces in dealing with China, in particular after American intelligence agencies had predicted that Mr. Xi would focus on economic development and follow the path of his predecessor, who advocated the country’s “peaceful rise.”
Secretary of State John Kerry arrived in Beijing on Saturday to discuss a variety of security and economic issues of concern to the United States, although it remained unclear whether this development with the missiles, which officials describe as recent, was on his agenda.
American officials say that, so far, China has declined to engage in talks on the decision to begin deploying multiple nuclear warheads atop its ballistic missiles.
“The Chinese have been reluctant to have that discussion in official channels,” Mr. Saunders said, although he and other experts have engaged in unofficial conversations with their Chinese counterparts on the warhead issue
Beijing’s new nuclear program was reported deep inside the annual Pentagon report to Congress about Chinese military capabilities, disclosing a development that poses a dilemma for the Obama administration, which has never talked publicly about these Chinese nuclear advances.
President Obama is under more pressure than ever to deploy missile defense systems in the Pacific, although American policy officially states that those interceptors are to counter North Korea, not China. At the same time, the president is trying to find a way to signal that he will resist Chinese efforts to intimidate its neighbors, including some of Washington’s closest allies, and to keep the United States out of the Western Pacific.
Already, there is talk in the Pentagon of speeding up the missile defense effort and of sending military ships into international waters near the disputed islands, to make it clear that the United States will insist on free navigation even in areas that China is claiming as its exclusive zone.
To American officials, the Chinese move fits into a rapid transformation of their strategy under Mr. Xi, now considered one of the most powerful leaders since Mao Zedong or Deng Xiaoping. Vivid photographs, which were released recently, of Chinese efforts to reclaim land on disputed islands in the South China Sea and immediately build airfields on them, underscored for White House policy makers and military planners the speed and intensity of Mr. Xi’s determination to push potential competitors out into the mid-Pacific.
That has involved building aircraft carriers and submarines to create an overall force that could pose a credible challenge to the United States in the event of a regional crisis. Some of China’s military modernization program has been aimed directly at America’s technological advantage. China has sought technologies to block American surveillance and communications satellites, and its major investments in cybertechnology — and probes and attacks on American computer networks — are viewed by American officials as a way to both steal intellectual property and prepare for future conflict.