Like so much discord in the digital age, it all began with a tweet. On Oct. 4, Daryl Morey, general manager of the Houston Rockets basketball team, posted an image showing support for Hong Kong’s pro-democracy protesters. The somewhat anodyne message of solidarity — which was later removed — unleashed a fire hose of acrimony. Chinese netizens and state institutions reacted with outrage over a perceived attack on Chinese sovereignty; American politicians in an increasingly anti-Beijing Washington decried Chinese nationalism; the U.S. National Basketball Association, the league to which the Rockets belonged, found itself awkwardly caught in the middle and issued a mealy-mouthed apology that only stoked the controversy.

The league later put out different statements in Chinese and English. A message posted on Chinese social media suggested NBA officials were “extremely disappointed” by what it deemed was Morey’s “inappropriate” comment. A subsequent message put out by NBA Commissioner Adam Silver purported to uphold American values on the world stage. “Values of equality, respect and freedom of expression have long defined the NBA — and will continue to do so,” Silver said Tuesday. “As an American-based basketball league operating globally, among our greatest contributions are these values of the game.”

The NBA has spent decades blazing a path into China, where it retains tens of millions of die-hard fans. The Rockets — who for years boasted towering Chinese superstar Yao Ming in their ranks — are especially popular. Their footprint in the world’s most populous nation proved deeply lucrative. But all of that steady corporate work seemed at risk in the aftermath of Morey’s tweet.

“It is not feasible to conduct exchanges and cooperation with the Chinese yet not understand Chinese public opinion,” declared China’s Foreign Ministry spokesman, Geng Shuang, on Tuesday.

That same day, China’s state television network announced it would withhold broadcasts at least for this week of the NBA’s preseason games. A series of Chinese brands, including smartphone maker Vivo and the Luckin Coffee chain, severed sponsorship deals with the American league. Criticism also came from Tencent, the major Chinese tech firm that has a $1.5 billion streaming deal with the NBA. In the United States, Republican senators and Democratic presidential candidates all cajoled the NBA to stand its ground and not cave to this form of political correctness with Chinese characteristics.

Though the protests in Hong Kong have struck a particularly sensitive nerve in China, the current spat is hardly a stand-alone occurrence — and it may be a sign of things to come. “As China’s economic clout expands, its government and consumers are coercing international companies and punishing speech they deem critical, adding a growing element of unpredictability for foreign executives weighing the opportunities and risks of doing business in the country,” explained The Post’s Gerry Shih.

There were other incidents just this week. After a recent episode of the irreverent American cartoon comedy “South Park” mocked how Hollywood studios and executives create content these days in fear of Chinese censorship, Chinese censors followed through and carried out a sweeping purge of the show from Chinese streaming sites and social media pages. Blizzard, an American video game company that counts Tencent as a part investor, became the target of an Internet boycott after it banned a champion esports contestant who called for Hong Kong’s liberation and stripped him of his prize money.

In the past, other Western companies have suffered similar censure. Mercedes-Benz apologized for hurting “the feelings of the Chinese people” when it cited the Dalai Lama, Tibet’s spiritual leader in exile, in an Instagram post. Companies as disparate as U.S. airline Delta and Spanish fashion brand Zara both issued groveling apologies after publicly listing operations in Taiwan — which China views as a breakaway province — as a separate country from China on its website.

There’s nothing new about Chinese nationalist anger. But Beijing’s political tensions with Washington and China’s growing global clout are forcing multinational firms to pay attention. “These dynamics have gone on for a long time,” tweeted Paul Mozur, a China tech correspondent for the New York Times. “The Hong Kong protests are causing China’s underbelly of speech control to go mainstream in a huge way. The more Beijing pushes for control, the more the global narrative will slip away from it, and it won’t be pretty.”

The current disputes underscore a now inescapable reality of global politics. Many U.S. firms — along with corporate behemoths like the NBA — went into China insisting that their forays into a vast, untapped market would bring the world closer together. The opening of China’s economy, many genuinely believed, would be followed by an inexorable liberalization of Chinese politics and society.

That has not happened. Instead, the events of the past week have only reinforced widespread fears among U.S. analysts over China’s corrosive influence on Western practices and norms. If China can browbeat foreign firms so easily now, what will the status quo look like two or three decades from now, when the habits and demands of the Chinese middle-class consumer will have an even greater impact on the global economy?

China “has been rising for more than 40 years, unaccompanied by effective public pressure for reform. It opted in to the liberal order without liberalizing,” wrote Kori Schake, a former Bush administration official, in an essay published last year. “Despite President Xi Jinping’s expansive statements about preserving the liberal order, China undercuts it politically, economically, and militarily.”

China’s touchy feelings over Hong Kong, meanwhile, obscure the genuine sense of crisis brewing in the former British colony. Beijing looks unlikely to concede much, while a hardcore segment of Hong Kong pro-democracy protesters are turning more and more radicalized. “The calculus of Communist rule does not allow for concessions to unruly provinces,” noted Jamil Anderlini of the Financial Times. “If Xi were to compromise and grant Hong Kong the right to vote for its leaders then what about Shanghai or Shenzhen? If he does not harshly punish the territory then the rest of the nation and his many political enemies would smell weakness, rather than applaud his restraint. Because the people of Hong Kong instinctively understand what is coming, they are unlikely to quietly return to their ordinary lives.”

The upheaval has already been deeply damaging for foreign companies operating in the city, where both protesters and Beijing’s pressure campaigns have targeted businesses believed to be favoring the other side.

“Hong Kong as Asia’s world city is finished. There is no way that Hong Kong can recapture its reputation as an efficient, safe, well-governed, orderly place to live and work and do business anymore,” Mike Chinoy, a Hong Kong-based nonresident senior fellow at the University of Southern California’s U.S.-China Institute, told my colleagues. “Some of this stuff you can’t put back together.”