John Ruwitch

In recent weeks, U.S.-China relations have unraveled with alarming speed, and some analysts say they are now at their worst since the two countries normalized diplomatic ties in 1979.

On Tuesday, the Trump administration ordered China's consulate in Houston to close, a step that significantly amps up the tension in already fraught relations between the world's top two economies.

Before Justinian Huang left Shanghai for some beach time in Malaysia last winter, he took his dog Swagger to stay with a friend.

"I dropped him off. I kissed him goodbye. I was like, 'I'm going to see you in six days,' " Huang recounts. "That was Jan. 23 of this year."

That week the coronavirus spread with alarming speed in China. So Huang decided to wait it out in Malaysia a few extra days. Then he flew to Taiwan, where he has family, and finally home to the United States.

The Trump administration on Thursday put visa and asset sanctions on several Chinese officials — including Politburo member Chen Quanguo — for what it says has been their role in "gross violations of human rights" in China's far western region of Xinjiang.

The move comes at a time when U.S.-China relations are at their worst in decades and is likely to anger Beijing, potentially leading to similar sanctions from China on American officials.

Attempts to dissuade China's ruling Communist Party from asserting more authority over Hong Kong didn't work. Now that China is imposing a new national security law on the territory, world powers are looking to punish Beijing.

The law hands the central government almost unchecked legal power in the former British colony, which was promised a "high degree of autonomy" for 50 years when it was returned to China in 1997. Drafted secretly and enacted swiftly on Tuesday, it is considered by many analysts to be even harsher than expected.

The Trump administration on Monday labeled four more Chinese news organizations as "foreign missions," expanding its restrictions on what it calls Chinese propaganda outlets in a move that's likely to anger Beijing.

Secretary of State Mike Pompeo met China's top diplomat Yang Jiechi in Hawaii on Wednesday, in what Chinese state media said was a constructive exchange of views.

The meeting comes at a time of fast-deteriorating relations between Washington and Beijing over a range of issues, including human rights, Hong Kong and the COVID-19 pandemic.

Neither the U.S. nor China publicly announced the meeting in advance and it was not immediately clear which side had proposed it, highlighting the tension and mistrust that now permeate ties between the world's no. 1 and no. 2 economies.

Protests across the United States in the wake of George Floyd's death have created an unlikely opportunity for China.

State TV has aired images of chaotic protest scenes during its widely watched evening news program, and offered searing commentary that has also highlighted the U.S. government's handling of the COVID-19 pandemic. "American politicians must ask themselves," one announcer said, "on what grounds do they spew their sanctimonious nonsense? Shouldn't they ask the American people for forgiveness?"

Secretary of State Mike Pompeo declared this week that Hong Kong is no longer sufficiently autonomous from China "to warrant treatment under United States laws in the same manner as U.S. laws were applied to Hong Kong before July 1997." The decision followed Beijing's announcement that it would draft sweeping national security legislation for the former British colony, sidestepping the city's own legislature to outlaw secession, subversion and terrorism.

The race for a coronavirus vaccine is on.

This week, Massachusetts-based Moderna Inc. reported promising preliminary results for the vaccine it is developing. It's one of eight vaccines under development that have been approved for clinical trials, according to the World Health Organization.

Updated at 9:41 p.m. ET

Secretary of State Mike Pompeo on Monday blasted the head of the World Health Organization for bowing to Chinese pressure and not inviting Taiwan to attend the body's annual meeting, damaging its credibility at a crucial time.

The World Health Assembly started on Monday amid the worst pandemic in modern history.

Taiwan's handling of COVID-19 has won plaudits around the world, creating a historic public relations opportunity for the diplomatically isolated island.

Whether that leads to a higher profile on the international stage or a flare-up in tensions with Beijing — which regards Taiwan as Chinese territory — will depend on how the two sides play their cards at this pivotal moment, experts say.