Chinese troops have been stationed in Hong Kong since the British left in 1997. Usually the soldiers keep a low profile. Months of unrest in the city, however, have fueled anxiety that China might mobilize them to restore order -- as it did 30 years ago in Tiananmen Square in Beijing. Chinese officials seemed willing to feed the speculation with hints and signals, including a video in August showing troops just across the border practicing riot-control techniques. In mid-November, dozens of People’s Liberation Army soldiers emerged from their barracks in shorts and t-shirts to help clear roadblocks left by pro-democracy protesters, a rare move that raised more alarm. Many see a military intervention as unlikely given the enormous political repercussions it would surely have. But just the possibility has set nerves on edge.

1. How many troops are there?

An estimated 6,000 are stationed in the city at any given time, with thousands more located across the border in Shenzhen, according to Rand Corp. But there may be more now. The Hong Kong garrison conducted a routine rotation in August, but unlike previously, there was no official announcement stating that the level of troops and equipment stationed in the city hadn’t changed, according to the South China Morning Post. Reuters reported in late September that the contingent had doubled in size since protests began, citing three foreign diplomats. The PLA’s Hong Kong headquarters sits in the city’s Central business district, a few steps from the Bank of America Tower, and there are barracks and other sites scattered across the city.

2. What do they do?

Generally keep to themselves, presumably engaged in drills and exercises (the PLA is very secretive). As far as helping out in Hong Kong, Article 14 of the city’s Basic Law states:

“The Government of the Hong Kong Special Administrative Region may, when necessary, ask the Central People’s Government for assistance from the garrison in the maintenance of public order and in disaster relief.”

The city government has never requested a deployment. In 2018, more than 400 soldiers helped clear fallen trees following Typhoon Mangkhut, the first time they had undertaken such a role. Some residents were disquieted as the city said it hadn’t asked for the help. It said the same in November.

3. What has China said?

China has defined its red lines as: “No harm to national security, no challenge to the central government’s authority and no using Hong Kong as a base to undermine China.” President Xi Jinping has repeatedly affirmed China’s support for Hong Kong leader Carrie Lam and the local police. But he also has refused to rule out a military intervention, and described restoring order as the city’s “most urgent task.” Chinese officials and state media have made charges of foreign interference, describing the U.S. as a “black hand” behind the protests -- a claim the State Department has dismissed as “ridiculous.”

4. And Hong Kong?

Lam has maintained that local authorities are fully capable of maintaining order and that there’s no need to ask China’s military for assistance. Asked at a Nov. 19 briefing about the clean-up action, Lam said it wasn’t uncommon for the garrison to get involved in charitable activities. “I suggest we do not over-interpret these voluntary acts,” she said.

5. And the PLA?

A spokesman for China’s military defended the decision by the local PLA garrison in Hong Kong to come out into the streets and help clean up. “Their efforts were welcomed by the Hong Kong citizens,” Senior Colonel Wu Qian said. “Ending violence and restoring order is the most pressing task we have in Hong Kong,” Wu said, echoing President Xi. In July, days after protesters surrounded China’s liaison office in Hong Kong and defaced the national emblem, Wu told a news conference:

“The behavior of some radical demonstrators, challenging the authority of the central government and touching the bottom line of the principle of ‘one country, two systems,’ is absolutely intolerable,” Wu said. “The Pearl of the Orient is not to be defiled.”

Also in July, the garrison released a three-minute video showing PLA troops in riot gear battling mock protesters with tear gas, water cannons and armored personnel carriers. “We have the determination, confidence and capability to safeguard China’s sovereignty, security and development interests, and to safeguard Hong Kong’s long-term prosperity and stability,” the garrison wrote.

6. What’s the fear?

Martial law or a state of emergency could be declared. The nightmare scenario is a repeat of the deadly crackdown by the PLA that took place in Tiananmen Square, in which hundreds or even thousands of people died. An alternative could be deploying the People’s Armed Police, a paramilitary force used to guard sensitive sites like Tiananmen and in the predominately Muslim western region of Xinjiang. The South China Morning Post reported that some of the troops that came out to clear roads in November were from an elite counterterrorism brigade.

7. What might happen then?

Even smaller-scale intervention could spark an exodus from the city’s financial markets and prompt international companies to consider pulling out, especially if the U.S. were to withdraw Hong Kong’s special trading privileges. The economy would suffer, property prices would likely fall and Hong Kong’s cosmopolitan image would suffer major damage.

8. Wouldn’t China suffer?

China would face potential economic sanctions from the U.S. and Europe, an emboldened pro-independence movement in Taiwan and increased financial risks for companies that rely on Hong Kong as a gateway to international investors -- all while grappling with U.S. President Donald Trump’s trade war and the slowest economic expansion since foreign investment collapsed after Tiananmen.

9. What are others saying?

The U.S. State Department on Nov. 11 called on all parties to exercise restraint and find a humane solution. Lam was quoted by Reuters in September as having said China wasn’t planning to deploy troops because “the price would be too huge to pay.” Hu Xijin, the editor of the Global Times, one of China’s most combative state-run newspapers, wrote in July that troops would only be deployed in extreme cases, such as a takeover of the city’s main government institutions by extremists.

--With assistance from Dandan Li, Natalie Lung, Chloe Whiteaker, Michael Patterson and Peter Martin.

To contact the reporters on this story: Iain Marlow in Hong Kong at imarlow1@bloomberg.net;Jeanny Yu in Hong Kong at jyu107@bloomberg.net

To contact the editors responsible for this story: Brendan Scott at bscott66@bloomberg.net, Paul Geitner, Karen Leigh

©2019 Bloomberg L.P.