Gen. Charles Brown Jr., who leads the Air Force and who could be the next leader of the Joint Chiefs of Staff, put out a warning Friday that China is targeting US troops. The letter sent to all Air Force personnel and warns that China is looking to recruit people with knowledge of US operations.

It marks the Pentagon’s most direct attempt yet to call out and counter what U.S. officials characterized as an aggressive ploy by Beijing to leverage international firms that hire Americans to teach advanced military skills and tactics…

“By essentially training the trainer, many of those who accept contracts with these foreign companies are eroding our national security, putting the very safety of their fellow servicemembers and the country at risk,” Brown wrote, appealing to the recipients’ sense of responsibility, even after leaving the armed forces, to protect “our national defense information.”

China has really been working on this particular form of spying for years. What is being described here is not so different from the approach China takes with US academics who have been offered positions at Chinese universities which pay extremely well (the Thousand Talents program). In exchange the professors agree to teach in China on some area of expertise that China can’t reach on its own. Instead of stealing the information, China has simply decided to pay for it.

A special agent with the Air Force Office of Special Investigation, who like some others interviewed for this report spoke on the condition of anonymity to discuss a sensitive national security matter, said that attempts by China’s military to exploit Americans have included marketing job openings to them that initially appear innocuous and approaching them directly at defense industry events…

The offers come from a mix of privately owned companies and those backed by the Chinese government, and are contracted by the Chinese government, officials said. The solicitations often include language that sounds customary in the defense sector, with references to consulting, advising or training.

It’s not just the US that is being targeted in this way. Last year I wrote about retired British Air Force pilots who were being recruited to train the Chinese in how to defeat western warplanes.

China has recruited dozens of former British military pilots to teach the Chinese armed forces how to defeat western warplanes and helicopters in a “threat to UK interests”, officials have revealed.

One official said some 30 mainly ex-fast jet but also some helicopter pilots – lured by annual salaries of around £240,000 – are currently in China training pilots for the People’s Liberation Army, in what a defence analyst described as a stunning breach of security.

A retired senior Royal Air Force officer said: “Wow… that is appalling. What were they thinking?”

I can tell you exactly what they were thinking. They were thinking that $300k a year is a damn good salary. Simply put, they sold out.

The letter released today comes just days after reports circulated about Chinese nationals working as “gate-crashers,” i.e. trying to gain access to US military bases. In some cases these infiltrators have actually tried to push past guards. When they are stopped, they offer a scripted reply claiming to be tourists who have somehow gotten lost.

As Ed noted when he wrote about it, some version of this practice has been going on for years. Previously the gate-crashers often consisted of Chinese “diplomats” who hid behind their diplomatic credentials when caught. Now China has shifted to using people who can’t be directly tied to the Chinese government. Many of them won’t get through but by sending a lot of them, some will succeed.

Looking at the overall pattern we also can’t forget about the Chinese spy balloon that drifted over US bases back in February. China is doing everything it can to beg borrow and steal information on the US military. It makes you wonder if this is just China’s usual penchant for stealing information so it can copy what works without doing the work themselves or if Xi Jinping really thinks he is preparing for a military conflict with the US. That is what Xi himself says he is doing.

Chinese leader Xi Jinping says he is preparing for war. At the annual meeting of China’s parliament and its top political advisory body in March, Xi wove the theme of war readiness through four separate speeches, in one instance telling his generals to “dare to fight.” His government also announced a 7.2 percent increase in China’s defense budget, which has doubled over the last decade, as well as plans to make the country less dependent on foreign grain imports.

If he acts like he’s preparing for war and he says that he’s preparing for war, maybe we should believe him.