China will lead talks among the five original nuclear-armed states to define arms control terms, the group said on Friday, a first for Beijing and a step that might ultimately bring greater clarity about its nuclear arsenal and strategy.
A working group of the United States, Russia, Britain, France and China is expected to launch talks this summer on a glossary of nuclear terms, an arcane but necessary step for wider talks on disarmament.
Of the five original nuclear-weapons states within the nuclear Non-Proliferation Treaty, China is the most secretive about its arsenal, its stockpile of fissile material and its nuclear doctrine, analysts say.
Under the treaty, which entered into force in 1970, the five committed to pursuing disarmament while the other signatories committed not to develop or acquire nuclear weapons.
Rose Gottemoeller, the acting U.S. under secretary of state arms control and international security, said the United States and Russia have a far better grasp of each other's nuclear posture than they do of China's.
China's leadership of the so-called P5 group, described in a statement issued by the five nations on Friday at the end of a three-day conference, could signal its greater interest in cooperating on these issues.
A U.S. official who spoke on condition of anonymity said this was the first time China had chaired such a P5 group on nuclear issues.
"It's a very good step," Gottemoeller told Reuters. "The fact that they are shouldering the responsibilities for this working group, I think, is a good sign of their interest of developing more mutual cooperation of this kind, leading to greater predictability and greater mutual confidence."
Gottemoeller stressed the group's aim was to achieve greater openness about all five countries' programs.
"(For) over 40 years with the Soviet Union and now the Russian Federation we have been talking about important issues of nuclear doctrine, strategy and then some of the technical nitty-gritty that goes into an arms control treaty," she said.
"We really have a lot of history with the Russian Federation but certainly with China, we do not have that same depth."
Daryl Kimball, executive director of the Arms Control Association nonprofit group, said the United States has been the most transparent about its nuclear capabilities and Britain, France, Russia and especially China "have a long way to go."
"China ... has been the least forthcoming," he said. "With transparency comes greater knowledge, greater understanding and more stability, more predictable reactions (by) others."
According to Arms Control Association estimates, the United States has about 5,000 warheads, Russia 5,500, China about 240, France fewer than 300 and Britain up to 225.
Stephen Rademaker, a former senior State Department official under President George W. Bush, said the United States may hope that the talks on definitions could be a first step toward greater clarity on China's capabilities.
"The United States for a long time has tried to initiate a comprehensive dialogue with China about nuclear matters and, unfortunately, China has resisted discussing those kinds of issues in any level of detail," he said.
"I am sure that the United States hopes that as part of this ... process, the kinds of conversations that have not ... made much progress bilaterally can finally begin," he added.