The U.S. government has banned American government personnel in China, as well as family members and contractors with security clearances, from any romantic or sexual relationships with Chinese citizens.
Diplomats know it by heart, night and day - to recruit a person, you need to know what they're vulnerable to and what moves them. Can they be manipulated with greed, shame, ambition, even their sense of justice or compassion? If you know, you can plan your steps towards obtaining their assistance - either in a single case or permanently.
People living in a foreign land are uniquely vulnerable to loneliness, so attracting their romantic interest is an age-old method.
It works domestically too - for example in the UK, a dozen cases are known where undercover cops have befriended activists and even had children with them. If it's not beyond the law enforcement of a democratically elected government, it is absolutely within the methods (and perhaps a preferred method) of an authoritarian government which cares less about people's rights.
Perhaps for this reason, diplomats often bring families along, as to not have issues of loneliness or temptation, since they live abroad for most of their careers. Ordinary embassy workers probably get a short lecture. First about honey traps, secondly about serious pressure from the local government that may target any of their genuine romantic relations. Basing on this, they would be expected to manage their risk. Apparently, someone decided they cannot handle it.
Has China stepped up efforts to recruit embassy workers? Maybe... but that's probably confidential. Alternatively, someone just got extra worried. This kind of policy changes would benefit from a bit of transparency, e.g. some three letter agency writing in their journal that "we detected a 200% rise in recruitment efforts".
In many American military bases around the world, they disallow their personnel to engage in nightlife outside their base and hand-pick prostitues for them who are hardly 18 and don't speak a single english word. you can look up their storis and testimonies on Youtube
People being incentivised to keep these relationships secret just gives even more leverage to the CCP if they successfully use this as an espionage tactic. I assume that's what this is meant to guard against but surely it would have the opposite effect wouldn't it?
The headlines leave out the part where this is a requirement of their security clearance. It is not uncommon for those holding a security clearance to be discouraged or prohibited from relationships with foreign nationals. It also isn’t a direct prohibition, it would just result in a loss of their clearance, and you are absolutely correct that this will result in more leverage against US personnel.
What they don't mention in the movies is how many of those women he got pregnant and had to pay child support to(except Craig Bond). I suppose he was enough of a blunt instrument that they didn't have to worry about him getting blackmailed or otherwise selling state secrets because they never really gave him intel of much value.
No, every person American employs outside of the US is a bad, counterrevolutionary, child eating spy. Now face the wall comrade, we found out you spoke english that one.