“To me, Beijing would like nothing more than the U.S. to remove Hong Kong’s special status. I don’t really get it. I don’t understand what game they think they are playing,” said Thornton, who retired from the Department of State in July after more than 25 years of service, referring to U.S. lawmakers pushing the bill.

The career diplomat, who has held overseas postings in China, Central Asia, Russia and the Caucasus, said the proposed legislation reflected a misinformed political conversation in the United States about China and Hong Kong.

“I don’t think they think about it much, but they just have this one bill that has Hong Kong in it, and they’re wielding it like a club, and they don’t seem to understand that the club is basically going to whack the Hongkongers upside the head, and the Beijingers will be dancing in the streets.”

Thornton, who is now a senior fellow at Yale University’s Paul Tsai China Centre, said that rather than trying to punish Hong Kong, the U.S. should be seeking to act as a “moral compass”. She accused Washington of being “irresponsible and misinformed” with its remarks on the recent unrest in the city, arguing that U.S. officials should express disapproval of violence from all sides.

“Condemning violence on the part of the protesters, rather than cheering them on because they are singing the U.S. national anthem, I think, would be appropriate, but also condemning police violence,” she said. “Basically just saying the right things, which we haven’t been doing.”

Republican Sen. Marco Rubio, who introduced the bill in June, has said it aims to “hold China to its promise” to respect the autonomy and freedoms afforded to Hong Kong under the Sino-British Joint Declaration that was signed before the city’s return to Chinese rule in 1997.

Hong Kong leader Carrie Lam Cheng Yuet-ngor has criticised the bill as an attempt to interfere in the city’s internal affairs, but local democracy activists such as Joshua Wong Chi-fung and Denise Ho Wan-sze have lobbied for its passage, which they say will guarantee and further the city’s democratic freedoms.

The Senate bill and a similar proposal in the House of Representatives have attracted the support of more than three dozen Republican and Democratic lawmakers since their introduction earlier this year. After clearing the committee stage, the proposed legislation is expected to go to a vote soon, possibly this month.

Under the U.S.-Hong Kong Policy Act of 1992, Washington treats Hong Kong differently from mainland China in areas including trade and export controls. The 2019 act, if passed, would require the U.S. government to assess Hong Kong’s level of human rights and democracy each year to determine whether Washington should continue to grant these trade privileges. It could also pave the way for diplomatic action and economic sanctions against the city’s government.

Hong Kong is in its 18th straight week of anti-government protests triggered by a now-scrapped extradition bill. Since October 1, China’s National Day, radical protesters have escalated vandalism and violence to new levels, trashing and burning shops, bank branches and subway stations.

Thornton was the longest-serving senior envoy for Asia under the administration of President Donald Trump. A formal nomination to become assistant secretary failed due to opposition in the Senate from China hawks such as Rubio. Since leaving the government, she has taken aim at Trump’s overall policy of confrontation with China in areas ranging from technology to trade.

“I think it would be much more productive to try to work with them constructively on that than to try to isolate them, keep them out, block their development and contest what they are doing in the world,” she said.

While acknowledging that the U.S. had legitimate complaints about China regarding market access and intellectual property protection, Thornton said Washington was in denial about the inevitability of Beijing exerting more influence in the world. Her country had resorted to a “dog in the manger” approach to China’s rise, she added.

“We are kind of delusional about our reality and what we are dealing with, I think,” Thornton said. “China is a country of 1.4 billion people, they opened up their country to the world in order to develop it, and the idea that we were going to stop them is not realistic.”

She said there was a widespread misconception that previous U.S. administrations had squandered opportunities to keep China “weak and poor” by engaging it in diplomacy and cooperation.

“The problem with that argument is that it assumes there is something we could have done to change the internal dynamics inside China – if we had foreseen the rise of Xi Jinping and his turn towards greater internal repression in Chinese domestic politics, that there’s something we could have done to alter or prevent that.”

On North Korea, Thornton said she was pessimistic about the prospects of Kim Jong-un relinquishing his nuclear weapons, but expressed disappointment that the Trump administration had not tried to exploit the dictator’s reported interest in economic development for his impoverished country.

“My unceasing desire has been for people to seriously test that proposition by offering something, and seeing what they are willing to do on denuclearization,” she said. “But so far, we haven’t really managed to offer anything where people would reasonably say: ‘Oh yeah, well that’s something that’s really important for their economic development, so if they are not willing to do anything on denuclearization to get that, it’s obvious that they are not willing to do anything, period.’”

Thornton also expressed skepticism about Washington’s efforts to stop Pacific Island nations from switching their diplomatic allegiance from Taiwan to mainland China. The Solomon Islands and Kiribati last month became the latest countries to ditch Taipei, bringing the self-ruled island’s number of diplomatic allies to 15.

“I think what we also have to realise in this diplomatic game is that as China’s influence and weight in the international system grows, it’s going to be harder and harder for countries to justify recognizing Taiwan, no matter what kind of dollar diplomacy or other things are happening,” she said. “So the idea that the US is trying to shore up Taiwan’s diplomatic allies is probably not a very strong hand to play in the long term.”