I had a work-study job in college at our small local airport working for the FAA. I mostly clipped new FAA communications into 3-ring binders and tore off expired ticker tape weather reports for a couple of hours a day.
My boss was old school government employee, straight and square. One day we were talking and he handed me a FAA business card with a UFO reporting 800 phone number. Odd I thought, and put it in my wallet.
Years later I lost my wallet in a phone booth (am old). I got a call from someone who found my wallet and wanted to return it. He came over with the wallet which had everything still in it, including cash. The only thing missing was the UFO card. I've never seen another one.
The Chinese response was amusing - they didn't deny spying with balloons, but rather said 'You STARTED it by spying on US with balloons!' - which the US denied.
Is the US lying, and they are floating spy balloons over China? Again, it seems unlikely because satellites exist, but it could be exactly the sort of response testing you're thinking of, going both ways.
The funniest possibility, of course, is that the winds are blowing both American and Chinese weather balloons out over each other's territory, and both nations think each other's weather balloons are spy balloons, because of course they do.
anything chinese outside their borders is primarily for espionage.
Yes, but you realize balloons go wherever the wind carries them, right?