Thousands of protesters joined the occupation of Hong Kong’s international airport yesterday, forcing authorities to cancel all flights from the afternoon onwards. According to protesters, the airport occupation was a response to escalating police violence over the weekend with the use of tear gas, rubber bullets and batons.

The closure of the world’s eighth biggest airport, following on from last week’s general strike, the first in the city in decades, marks a significant deepening of the political crisis in Hong Kong. For the first time, the turmoil became a factor affecting stock markets, not only in the city but internationally, including in the US and Europe.

Hong Kong has established itself as a key financial and commercial hub in Asia and the primary gateway for investment and business between China and the rest of the world. Its airport is the busiest hub for international passenger traffic in Asia and the world’s largest for air cargo traffic. Hong Kong shares have lost nearly $500 billion in value since protests erupted in early June.

In worried comments to Bloomberg, Steven Leung, executive director of Uob Kay Hian (Hong Kong) Ltd, said that the unrest had been “longer and more violent than I had expected.” He warned: “As long as we keep having such incidents every week, no investors will buy assets in Hong Kong.”

Amid declines in the European markets, analyst Neil Wilson told AFP: “Hong Kong has kind of been under the radar of most traders… but increasingly I feel that this has the potential to spiral into a bigger market worry. Today’s moves highlight the risks.”

With the mass protest movement now in its 10th week, there is no sign that the protesters will back away from their demands for the withdrawal of a controversial extradition law, the resignation of Chief Executive Carrie Lam, an independent inquiry into police violence, the withdrawal of charges against protesters and free and open elections based on universal suffrage.

Early reports today indicate that the protest at the airport is continuing and a number of flights have been cancelled. The Civil Human Rights Front, which has organised several of the huge, early protests against the extradition law, announced yesterday that it would hold another mass march this coming Sunday.

The Chinese regime stepped up its denunciation of the protests yesterday. In Beijing, Yang Guang, spokesman for China’s Hong Kong and Macau Affairs Office, branded the demonstrations over the weekend as “deranged.” He claimed that radical protesters had used “extremely dangerous tools to attack police officers,” saying: “The first signs of terrorism are starting to appear.”

Yang declared that Hong Kong had “reached an important crossroads.” While continuing to express support for Hong Kong’s police and judiciary, he declared that violent acts had to be severely punished “without leniency, without mercy.” His remarks are the latest indication that the Chinese Communist Party (CCP) regime in Beijing is considering the use of its military to suppress the protests.

The CCP is extremely nervous that the protests, and particularly last week’s general strike, will trigger social and industrial unrest across the border on the Chinese mainland. Workers and young people throughout China, including Hong Kong, confront deteriorating social conditions and restrictions on basic democratic rights.

Hong Kong was handed back to China in 1997 on the basis of the formula “One country, two systems” that was to allow substantial autonomy for the city. In reality the concern of Britain and the ruling elites in Hong Kong was to protect business interests, not the democratic rights of the people of Hong Kong. China only made cosmetic changes to the anti-democratic methods of colonial rule used by Britain since 1841.

The US and its allies have adopted a deliberately low-key approach to the Hong Kong protests, despite Chinese accusations that Washington is the “black hand” behind the political unrest and is seeking to foment a “colour revolution.”

Speaking to reporters in early August, President Trump branded the protests as “riots” and said: “Hong Kong is part of China, they’ll have to deal with that themselves.” His remarks reflect fears in the ruling classes in Washington and internationally, that the protest movement in Hong Kong is part of a broader resurgence of the working class around the world.

Despite criticism in the media and political establishment, and the escalating US economic war with China, Trump has not resiled from those comments. However, as the political crisis in Hong Kong worsens, the demands in Washington for the Trump administration to take a tougher line against Beijing over the issue have intensified.

In a tweet yesterday, US Senate Majority Leader Mitch McConnell warned China that any violent crackdown on the Hong Kong protests would be “completely unacceptable.” Cynically posturing as a defender of human rights, he declared: “The people of Hong Kong are bravely standing up to the Chinese Communist Party as Beijing tries to encroach on their autonomy and freedom.”

In comments to the media, an unnamed senior Trump official maintained the hands-off approach. While urging all sides to refrain from violence, the official said that the protest movement was a matter between China and Hong Kong.

Britain has adopted a similar approach. British Foreign Secretary Dominic Raab spoke over the phone to Hong Kong Chief Executive Lam last Friday and called for an end to violence on all sides, while formally supporting the right to peaceful protest. He called for political dialogue between the two sides and an independent inquiry into the events.

Beijing quickly dismissed his comments. Foreign ministry spokeswoman Hua Chunying declared that the days when Britain ruled Hong Kong were “long gone.” She criticised “foreign interference” in Hong Kong affairs, saying: “It is simply wrong for the British government to directly call Hong Kong’s chief executive to exert pressure.”

While some Hong Kong protest leaders have appealed to the US, Britain and other imperialist powers for support against China, any intervention by Washington and its allies would be to further their own economic and strategic interests, not democratic rights in Hong Kong and throughout the rest of China.