In one fell swoop, more than a dozen veteran titans of Hong Kong’s democracy movement were arrested on Saturday (April 18) for their roles in last year’s large-scale protests.

While the government has been detaining opposition figures with increasing frequency—including an ominous midnight arrest of a local councillor on charges of sedition—the weekend’s mass arrest is unprecedented in scale and prominence, and signals a major step-up in China’s crackdown on the city’s opposition movement.

The arrests came as China is just starting to emerge from its first wave of the coronavirus epidemic, newly triumphant about its success in quickly containing the outbreak while countries around the world—notably Western democracies—continue to struggle with mounting fatalities and overwhelmed medical systems.

Among the 15 arrested were media tycoon Jimmy Lai, whose Apple Daily newspaper is trenchant in its disdain for China’s Communist Party; heavyweight lawyers Margaret Ng and Martin Lee, and former opposition legislators “Long Hair” Leung Kwok-hung, Albert Ho, Lee Cheuk-yan, and Au Nok-hin, who was recently convicted of assaulting a police officer for speaking too loudly through a megaphone. They were all detained “in connection with organising and participating in unauthorised assemblies,” the government’s security bureau said.

Martin Lee, 81, widely known as Hong Kong’s “father of democracy,” said he was proud to finally be a defendant and join the ranks of those who’ve been prosecuted.

The arrests quickly drew widespread international rebuke, including from US attorney general William Barr, Democratic House speaker Nancy Pelosi, Democratic presidential candidate Joe Biden, and secretary of state Mike Pompeo. Australian foreign minister Marise Payne specifically called out China for using the coronavirus crisis as a cover, as did Jim McGovern, a US House Democrat and chairman of the Congressional-Executive Commission on China. The European Union’s spokesperson for foreign affairs said the arrests “demand close scrutiny.”

The Hong Kong government said the arrests were “not politically motivated,” and were carried out in strict accordance with the law. In the past month, however, Beijing has increased its calls for a controversial national security law to be enacted in Hong Kong, which critics say will further erode the city’s civil liberties. The central government has also claimed full authority in interfering in local Hong Kong affairs—something that the city’s mini-constitution expressly bars—and the Hong Kong government has backed that claim, but not without an embarrassing series of flip-flops.

In the past several weeks, China has cranked up its aggressive posturing on the diplomatic stage in an attempt to re-focus the coronavirus narrative from its initial missteps and cover-ups to its success in controlling the disease, which it has chalked up to the superiority of the Chinese political system. Its case for the strength of its authoritarian model has been bolstered by the fumbling epidemic responses of Western democracies.

It appears that China is leveraging the pandemic as a rare opportunity to make aggressive gains across multiple fronts, betting that it will face minimal meaningful pushback from foreign governments distracted by their own epidemic response. Chinese government officials and academics have already framed the coronavirus crisis as a chance to advance the overseas expansion of its companies. China has also of late renewed its activities in the disputed waters of the South China Sea.

China’s diplomats are also hitting out as foreign governments find themselves on their back feet. The Chinese embassy in France has endorsed the view that Western governments are leaving elderly residents to die in nursing homes, for example, while the ambassador to Botswana dismissed reports that Africans were facing discrimination in China by accusing the media of making “one-sided allegations.” Countries around the world, however, have summoned Chinese diplomats in protest of their rhetoric.

For foreign governments, the challenge will be to identify China’s maneuvers and respond adequately, even as a domestic health crisis continues to unfurl. In particular, the arrests now present the US with a concrete scenario with which to evaluate how to enforce the Hong Kong Human Rights and Democracy Act, passed last November. The law requires the government to assess whether Hong Kong should continue to enjoy a special US trade and economic benefits, like being shielded from tariffs on Chinese goods.

Hong Kong appears to have weathered the first wave of the coronavirus epidemic with relative success, but there are fears that the government will use public health restrictions to clamp down on protests once the pandemic subsides. Already, there have been instances of what looks like a selective enforcement of health rules to target the protest movement.

Though large-scale protests have taken a hiatus due to the pandemic, the resistance movement is by no means over as people’s grievances over an unaccountable police force, eroding freedoms, and an undemocratic government remain unaddressed. The mass arrests have only deepened them. A number of crucial dates now loom on the horizon: the Tiananmen Square vigil on June 4; the first anniversary of last June’s million-person march, and the annual July 1 march. A boiling over of public anger looks likely, in whatever form that might take in Hong Kong’s post-pandemic world.