Tensions between the world's two largest economies have been on the rise again this week after the United States ordered the closure of China's Houston consulate, alleging it was a nest of Chinese spies who tried to steal data from facilities in Texas.
In a retaliatory move, China then ordered the US to close its consulate in Chengdu, accusing its staff of meddling in its internal affairs.
But espionage experts say the gathering of intelligence is a key part of what diplomatic missions do, and that often includes not only legal means but also the use of spies to gather "secret information".
"They do it, we do it. We just hope to catch them at it, and hope they don't catch us," said Anthony Glees, an internationally published expert on security and intelligence and professor of politics at the University of Buckingham.
"This is all part of the 'great game'."
To a certain extent, states chose to "turn a blind eye" to much of this activity because "it's in their mutual interests to do so", Professor Glees told the ABC.
The plethora of secrets revealed by Edward Snowden in 2014 included detailed information about how the US uses its own diplomatic missions to spy on countries across the globe, but no US consulates were shuttered as a result.
But this accepted spying culture does have limits, and crossing that line can, albeit rarely, result in diplomatic expulsion.
Here we look at past examples, and why China's Houston consulate one of five Chinese consulates in the US, along with the embassy in Washington DC was singled out.
Senior US officials said that espionage activity by China's diplomatic missions was occurring all over the country, but its activity out of the Houston consulate went well over the line of what was acceptable.
US Secretary of State Mike Pompeo called the consulate "a hub of spying and intellectual property theft", an allegation China rejected as "malicious slander".
Beijing is spending billions training up foreign journalists, buying up space in overseas media, and expanding its state-owned networks on an unprecedented scale.
A senior State Department official also linked espionage activity from that consulate to China's pursuit of research into a vaccine for the new coronavirus.
Professor Glees said Houston was currently a hotspot of information due to its aerospace and pharmaceutical research facilities, in particular in the midst of the COVID-19 pandemic.
"I'd have no doubt that the Chinese in Houston were hoovering up intelligence. It's one of just a few Chinese consulates, but in terms of leading-edge research probably the best place to be," he told the ABC.
But Professor Glees went on to pose two important questions.
"Was China trying to do this secretly and therefore unlawfully? One would guess it was, but it does not necessarily have to be so," he said.
"Does the USA, the UK, Australia do the same thing? Of course."
China's countermove to close the US consulate in Chengdu may have also been a choice based on strategic location.
"That is where the US gathers information about Tibet and China's development of strategic weapons in neighbouring regions," said Wu Xinbo, a professor and American studies expert at Fudan University in Shanghai.
The closure of embassies amid espionage allegations is rare, but diplomats accused of spying have been expelled in the past.
In 2018, 153 Russian diplomats were expelled by the United Kingdom and allied countries following the attempted poisoning of former Russian double agent Sergei Skripal and his daughter in the British town of Salisbury.
Russia responded by expelling 23 British diplomats and ordered the closure of the UK'sconsulate in St Petersburgand theBritish Counciloffice in Moscow.
At the height of the Cold War, Britain expelled 25 Soviet diplomats after the defection of Oleg Gordievsky, a former head of KGB operations in London, who had named KGB personnel operating in the Soviet embassy in London.
In Canberra, the Soviet embassy was closed down in 1954 when an intelligence officer based in the capital defected, offering to provide information about Soviet espionage activity against Australia and the West. The embassy reopened in 1959.
While the expulsion of diplomats and, even more so, the closing of an embassy is rare outside of war, Professor Glees said forced entry into the consulate of another state was "an absolute no-no".
But shortly after the closure of the Houston consulate, a group of men who appeared to be American officials were seen forcing open a back door of the building.
After the men went inside, two uniformed members of the US State Department's Bureau of Diplomatic Security arrived to guard the door.
China condemned the break-in saying it was in breach of both the Vienna Convention on Consular Relations and the China-US consular treaty.
"The US action right now is almost certainly unlawful," Professor Glees said.
"But they'll get away with it because Trump is up for re-election and having a go at China right now makes political sense even if there's no particular reason, to be honest."
Professor Glees said consular staff who were formally listed and known to host countries can operate as "legal spies", but they are required by law to abide by certain rules.
This intelligence gathering, whether secret or overt, can be done in many ways such as through meetings, conferences and visiting universities, businesses or research centres.
The uniform, the spy novels and a secret life. The breadcrumbs that suggest Australian citizen Yang Hengjun, detained in China for more than a year, was once a Chinese intelligence officer.
"Then you have the 'illegals' officers and agents who are not listed in any embassy rosters assuming an identity or simply using an existing reason for being in the receiving country to undertake espionage on the side," he said.
But even "legal spies" sometimes engage in illegal espionage, most often by recruiting agents to act on their behalf.
Chen Yonglin, a formerChinesediplomat who defected toAustraliain 2005, said "espionage is normal for all governments".
He said while Chinese diplomats collect information openly "to avoid being accused of being involved in secret intelligence work", they may also be providing key assistance to covert operations.
"But most operatives are run independently by various [government] departments," he told the ABC, adding that in many cases Chinese state-run companies can provide a better safe house.
Mr Chen said most infiltration can be carried out more effectively through migration especially of skilled workers and experts.
Rather than using embassies or consulates, they may communicate directly with Chinese officials or meet in a third country, making these operations very difficult to detect.
Diplomats most commonly work to create connections and place students and experts within key research departments in order to openly obtain information on new technology and developments that can then be used by China, he said, adding that such activities are particularly extensive in Australia where the response to intellectual property theft has been "weak".
In contrast, the Trump administration has taken a particularly hard line against China in both trade and political dealings.
Issues ranging from trade to the coronavirus pandemic, China's territorial claims in the South China Sea and its clampdown on Hong Kong, have plunged relations between Washington and Beijing to what experts said is their lowest level in decades.
It's almost inconceivable that the immediate future of the global economy hangs on the erratic whims of Donald Trump, writes Ian Verrender.
Following the break-in at the now-closed Houston site, China threatened repercussions, and the White House has not ruled out the possibility of closing more Chinese diplomatic missions.
While in a related incident, a researcher who took refuge in the Chinese consulate in San Francisco after allegedly lying to investigators about her Chinese military service has also been arrested by US officials.
"As far as closing additional embassies, it's always possible," US President Donald Trump told reporters earlier in the week.
But Mr Chen said while the US seemed to be distancing itself from China, any further response from Beijing was likely to be restrained.
"China benefits extensively from globalisation," he said.
"China's economy is reliant on international trade and shared technologies and they do not want to risk a break with either the US or Australia."
Original post:
Why is the US accusing China's Houston consulate of spying? - ABC News