The US has banned staff in China from sexual relationships with Chinese citizens over fears that Beijing’s agents could pass secret information to the ruling Communists.
The ban – the first non-fraternisation policy publicly known about since the Cold War – underscores the increasing US suspicion of China as the two countries battle for global influence.
Nicholas Burns, the outgoing US ambassador, introduced the policy in January just before his departure from China.
A scaled-down version of it was brought in last summer, banning American personnel from engaging in “romantic and sexual relations” with Chinese citizens employed as guards and support staff at the US embassy and five other consulates.
Mr Burns took it one step further just days before Donald Trump took office, extending it to include any Chinese citizen.
It is not uncommon for American diplomats and other governmental officials overseas to engage in relationships and even marriages with the country’s citizens.
But intelligence services across the world have long used attractive men or women to obtain secret information, particularly during the Cold War.
According to Peter Mattis, a former CIA analyst, there have been at least two publicised cases of Chinese agents seducing American diplomats stationed in China.
The ban was first discussed when members of congress contacted Mr Burns to express concern that restrictions on such relationships were not stringent enough, two sources said.
The new policy forbids any form of “romantic or sexual relationship” with Chinese citizens, but it is not clear how these relationships are defined.
It applies to US diplomatic missions across mainland China, including the embassy in Beijing and consulates in Guangzhou, Shanghai, Shenyang, Wuhan and Hong Kong.
Americans vulnerable to coercion
Only those with a pre-existing relationship with a Chinese citizen can apply for exemptions.
If their exemption is denied, it has been reported that the couple must end their relationship or leave their position. Anyone who violates the policy will be ordered to leave China with immediate effect.
As well as its network of spies, Chinese state security obtains information through interrogating ordinary citizens, making those who date Americans vulnerable to coercion.
Last year, China warned its own citizens against “exotic beauties” seeking to trick them into releasing confidential information, in a move that analysts said indicated a growing sense of insecurity from China’s leadership.
Its ministry of state security reported a case of a Chinese man called Li Si, who was allegedly blackmailed by foreign spies after visited a nightclub during an overseas trip.