China's one-child policy has caused decades of sex-selective abortions and killing of baby girls that has resulted in over 30 million "unmarriageable" Chinese men, who are causing a rise in instability and sex trafficking, former ambassador and GOP presidential candidate John Huntsman wrote to Washington in a diplomatic cable newly released by WikiLeaks.

After Vice President Joe Biden said he was "not second-guessing" China's one-child policy during his trip to Beijing, all the GOP presidential candidates criticized both the policy and Biden, for seeming to endorse it. Even after Biden issued a clarification and called the policy "repugnant," House Speaker John Boehner (R-OH) said that was not enough and called on the administration to end its contributions to the U.N. Population Fund (UNFPA).

But while Boehner and some GOP candidates are new to the debate over China's one-child policy, Huntsman, who served as Obama's ambassador in Beijing and who adopted a Chinese girl years ago, warned of the policy's grave implications in a January 2010 cable.

"Abnormally high sex ratio at birth and excess female child mortality both contribute directly to the sex ratio imbalance in China," Huntsman wrote. "Social consequences of this imbalance include an estimated excess of over 30 million unmarriageable males, a potentially destabilizing force that threatens to cause unrest in the most economically marginalized areas, and could lead to increased gender violence through demand for prostitution and trafficking in girls and women."

He said there is general agreement that the "abnormally high sex ratio" is due to the selective abortion of girls and the "excess female mortality," is caused by the killing of baby girls after they are born. Both are due to the "interaction of a strong cultural preference and pressure for sons with China's strict birth limitation policy," Huntsman said.

Due to the policy, Huntsman explained that there are about 32 million Chinese men under 20 years old who will not be able to find female partners and are called "bare branches." Richer, urbanized men attract the available women, Huntsman said, meaning that the single men who can't find women are usually found in poor and rural areas, searching for sex.

"Increased demand for sex workers and shortage of women to marry could lead to more trafficking of girls and women for future brides or the sex industry," the cable said, adding that while the Chinese government has begun talking about this problem, it has yet to take basic corrective steps, such as criminalizing sex-selective abortions.

While most politicians have cringed upon seeing their name in WikiLeaks cables, the Huntsman campaign sees the cable as reinforcing their message on China and human rights. A senior advisor to Huntsman told The Cable today that the diplomatic cable is evidence that as ambassador, Huntsman championed human rights far more than the administration.

"Not only was he advocating behind the scenes, but he publicly spoke out on behalf of dissidents and human rights, even in his farewell speech," said the advisor. "Given the vice president's recent comments on the one-child policy, it's clear the Obama administration is incapable of leading on this issue -- something Ambassador Huntsman is unquestionably prepared to do,"

In that farewell speech, Huntsman said that the United States will continue to advocate on behalf of imprisoned Chinese dissidents, explicitly naming Liu Xiaobo, Chen Guangcheng and Ai Weiwei, who has since been released.

"The United States will never stop supporting human rights because we believe in the fundamental struggle for human dignity and justice wherever it may occur. We do so not because we oppose China but, on the contrary, because we value our relationship," he said.

Huntsman campaign spokesman Tim Miller said that the campaign could not discuss confidential cables, but said that as an adoptive father whose daughter was abandoned by her parents in China, Huntsman was intimately familiar with the impact of the one-child policy.

"One-child runs counter to the fundamental value of human life and has myriad other negative consequences including an increase in sex trafficking and prostitution, as well as a destabilization of the family unit," Miller said.

Secretary of State Hillary Clinton was criticized in early 2009 for seeming to back off the issue of human rights when dealing with the Chinese government. She said, "We know what they are going to say" and "Our pressing on those issues can't interfere on the global economic crisis, the global climate change crisis and the security crisis."

More recently, administration officials have been more public in their criticisms of China's human rights practices, often talking about the case of Ai Weiwei. Clinton called China's human rights record "deplorable," in a May interview with the Atlantic. "They're worried, and they are trying to stop history, which is a fool's errand. They cannot do it. But they're going to hold it off as long as possible," she said.