Emily Feng

Earlier this month, Chinese state media launched a domestic blitz depicting the Hong Kong protests as riots funded by the CIA. China-linked social media accounts then flooded Twitter and Facebook with thousands of pro-Beijing posts and targeted advertisements.

Social media companies are now pushing back.

As anti-Beijing protests in Hong Kong enter their third month, China's leaders face a new challenge: managing perceptions of the protests at home.

China is anxious the protests might inspire similar dissent on the mainland, where huge swathes of territory — including the regions of Xinjiang and Tibet — have also seen numerous instances of opposition to Beijing's governance.

When hundreds of thousands filled Hong Kong's streets on June 9 to protest a controversial extradition bill, the only mainland coverage came from China Daily, an English-language state newspaper geared towards overseas audiences.

It falsely labelled the march as one in support of the bill, which would allow extradition of some criminal defendants in Hong Kong to face trial in China. The state broadcaster, CCTV, kept its coverage to a minimum. China's government was silent.

Last Monday, China let the yuan drop to its lowest value since 2008. The currency is now trading at just over 7 yuan to the dollar.

Later that day, the U.S. Treasury Department promptly labeled China a "currency manipulator."

In 1978, President Jimmy Carter received a late-night call from Beijing. It was from his science adviser saying Chinese leader Deng Xiaoping wanted to send 5,000 students to the United States. "Tell him to send 100,000," Carter recalls parrying back.

Amid weeks of mass anti-government demonstrations in Hong Kong that have frequently turned violent, Beijing on Tuesday issued a stark warning to protesters: "those who play with fire will perish by it."

The remarks, at a news conference in Beijing, were made by Yang Guang, a spokesman for the Hong Kong and Macau Affairs Office of the State Council.

He said China has "tremendous power" to put down the protests and warned that anyone who engages in "violence and crimes ... will be held accountable."

China's yuan plunged to below 7 per U.S. dollar on Monday morning, the lowest valuation for the currency in 11 years.

The slide in value comes as the U.S. and China remain locked in a trade dispute, leading some analysts to surmise that the devaluation is retaliation for additional U.S. tariffs announced on Chinese goods last week.

"The drop suggests that the central bank of China is willing to weaponize the currency in light of the trade war," says Andrew Collier, managing director of Orient Capital Research in Hong Kong.

A sudden knock at one's door. An unexpected call to meet off campus. Surreptitious visits to family members.

When Facebook announced plans in June to launch a new digital currency called Libra, the news sent monetary officials scrambling in China.

That's because since 2014, the People's Bank of China has been looking into building its own, centrally controlled cryptocurrency.

"We will keep a close eye on the new global digital currency," Wang Xin, research director at China's central bank, said of Libra at a conference in early July in Beijing. "We had an early start ... but lots of work is needed to consolidate our lead."

Former Chinese Premier Li Peng, who became known as the "Butcher of Beijing" for playing a major role in the brutal crackdown on the Tiananmen Square student protests in 1989, has died at the age of 90.

China and the United States are locked in a trade fight, a technology race and competing world military strategies. Leaders of these countries seem to be pulling the world's two largest economies apart.

These tensions are especially felt by those living with a foot in each country. The NPR special series A Foot In Two Worlds reveals the stories of people affected because of their ties to both nations. Reports from both the U.S. and China show how deeply and broadly the two nations are connected and what's at stake as they reshape their relations.

A Trump administration decision to restrict the sale of U.S. technology to Chinese telecommunications company Huawei will disrupt global supply chains, say analysts, ramping up pressure on U.S. allies reluctant to join in efforts to shut out Huawei from advanced 5G mobile networks.

For the last 15 years, Addgene has dedicated itself to accelerating medical research. The nonprofit in Watertown, Mass., does so by sharing research materials globally, like chromosomal DNA, used in the search for breakthrough medical cures.

That could soon change.

Wang Wen proudly says that he has been to over 20 U.S. states. He flies between the U.S. and China every few months for his job as director of the Chongyang Institute for Financial Studies, a university think tank in Beijing.

At least he did until a few weeks ago, when he received an email from the U.S. Embassy in Beijing. His 10-year U.S. business visa had been abruptly canceled with no explanation. He was told he could apply for a single-entry business visa instead, if he was able to list his last 15 years of travel history.

China is remarkably successful at scrubbing its Internet of social dissent. Twitter and Facebook have been blocked ever since deadly ethnic riots in 2009. Chinese social media platforms employ armies of internal censors to take down posts, images and even emoji.

But this month, coordinated dissent has popped up in an unexpected place: GitHub, the world's largest open-source site that lets programmers collaborate on code. (GitHub is owned by Microsoft, which is an NPR funder.)