Washington expressed strong displeasure on Tuesday over the passage of the Hong Kong national security law, which gives Beijing sweeping authority to curtail democratic freedoms, even as US lawmakers debated what leverage they have to effectively apply pressure on China.

“We will not stand idly by,” Senator Marsha Blackburn, a Republican from Tennessee and member of the powerful Armed Services and Commerce committees, said on Twitter.

Senator Tom Cotton, a Republic from Arkansas, echoed the mood. “Xi Jinping and his Communist thugs must face severe consequences for crushing Hong Kong’s freedoms,” he said in a statement.

Cotton, an outspoken China hawk, called on the Trump administration to consider “all options at its disposal” aimed at denying Beijing the benefits of Hong Kong’s distinct economic privileges.

Last week by unanimous consent, the Senate passed a bill that could punish Chinese officials for violating commitments made under the Sino-British Joint Declaration and the Basic Law, the city’s de facto constitution, and Cotton urged the House of Representatives to pass companion legislation.

“Those complicit in snuffing out freedom, democracy, and human rights in Hong Kong must be held accountable,” Senator Chris Van Hollen, a Democrat who introduced the Senate version known as the Hong Kong Autonomy Act, said on Twitter.

The House speaker, Representative Nancy Pelosi of California, said in a statement that Congress was united “in support of freedom, justice and real autonomy for the people of Hong Kong,” echoing calls for Beijing to be held accountable.

Passage of the security law – which gives Beijing broad powers to punish protests and critics under vaguely worded sedition and terrorism provisions – was widely expected after China’s rubber-stamp National People’s Congress (NPC) approved the measure in May.

But the specifics were all but unknown by most NPC delegates or Hong Kong residents until Tuesday – after it became law.

Analysts said China likely underestimated the global resistance, assuming the world would be largely distracted by the pandemic and economic downturn.

“They miscalculated,” said Ho-fung Hung, a professor of political economy at Johns Hopkins University. “The international community, particularly the US, reaction to this is going to be quite serious. It will make Beijing pay quite a substantial price and cost the Chinese economy, hi-tech development and financial development, some troubles in years to come.”

In recent days, the European Union has joined the US in expressing its strong disapproval, echoed somewhat less forcefully by Japan and South Korea, among others. The US in recent weeks has also announced an end to preferential tariffs for Hong Kong, tighter restrictions on technology exports and sanctions on Chinese and Hong Kong officials, without providing specifics.

China’s Asian neighbours – including partners in the Belt and Road Initiative aimed at spurring regional development – will likely have a more muted reaction, but the implications of Beijing’s move are not lost on them, some said.

“The top leaders of these countries will not say too much because they all have lots of business ties with China,” said Victor Shih, chair in China relations at the University of California, San Diego.

“But I think privately, this serves as a serious warning to China’s neighbouring countries because all of China’s promises of autonomy, it’s just that,” he added. “If Beijing can use its economic and security coercive capacity to compel a territory to comply with its wishes, it will do so.”

The heavy-handed move in Hong Kong dovetails with more aggressive action on the edges of its territory, analysts said. In recent weeks Chinese soldiers have clashed with their Indian counterparts along their disputed border, killing several.

China in recent months has stepped up island-building activities, patrols and resource exploration in the South China Sea and flexed its muscles in the East China Sea and with Taiwan.

“Beijing’s actions in Hong Kong should not be viewed in isolation, but rather as part of a broader pattern of China working to gain greater control over its claimed territories along its entire periphery,” said Ryan Hass, a fellow at the Brookings Institution and former China director at the National Security Council.

In a statement, the Chinese Foreign Ministry termed the security law a “fundamental solution for Hong Kong to restore order, end chaos and resume stability” that “reflects the shared will of all Chinese people including Hong Kong compatriots”.

US analysts voiced concern over elements of the new law. The sedition provisions could apply to almost any “obstruction” of government functions, including legislators blocking a bill, they said. And terrorism provisions can theoretically apply to anyone who blocks traffic during an unapproved protest.

“Basically any act of defiance will be considered a crime and will be punished with minimum sentencing” of three years, said Shih.

The foreign ministry countered that the bill would be judiciously implemented. “We have every confidence in the bright prospects of Hong Kong,” it said.

The international community has acknowledged that it has limited leverage over China, but some expressed confidence that global displeasure and punitive steps could shape Beijing’s actions over time.

Britain recently said it would help many Hong Kong residents gain UK citizenship. Taipei has reacted similarly, adding in a statement on Tuesday: “Taiwan will not stand idly by.” And Washington has said it will consider similar immigration policies.

“It’s almost like a Saigon 1975 moment,” said Hung, referring to the end of the Vietnam war. “The world recognises that it’s lost. The best they can do is accept people who come from there.”

Tougher US restrictions on dual-use technology exports to Hong Kong could undercut the Greater Bay Area by cutting Chinese companies off from leading-edge technology, others said. “Now they’re all at risk,” said Hung.

The most effective, if rather blunt, tool Washington has is its grip over the global banking system through the US dollar’s global currency status, analysts said. This would allow the US to sanction individuals and financial institutions seen abetting Beijing in cracking down on Hong Kong.

China has apparently anticipated this under the new security law with a provision making it a crime to work with “foreign forces” that endanger national security, analysts said. This could apply to financial institutions that comply with US financial sanctions.

“The bank would be trapped between a rock and hard place. They could be arrested,” said Shih. “I think the combination of the potential US sanctions and this national security law will accelerate the decline of the financial industry in Hong Kong.”

Others expressed confidence that Hong Kong would adapt, albeit in less vibrant form, as it has done in the past.

One thing is relatively certain, analysts said. As Washington and Beijing face off over trade, a pandemic blame game and Hong Kong, expect more turbulence. “We should expect the overall action-reaction cycle in US-China relations to accelerate in the weeks to come,” said Hass.