I agree the visibility makes it worse, but my sense is that stratospheric balloon overflight is something that happens fairly frequently and most of the time do

I agree the visibility makes it worse, but my sense is that stratospheric balloon overflight is something that happens fairly frequently and most of the time does not cause diplomatic incidents (which explains why we heard nothing about it the 4-5 times it happened in the past several years). Another instance is this Google balloon that recently fell out of the sky in the Congo: https://twitter.com/kambale/status/1621811081206439937 https://twitter.com/kambale/status/1621811081206439937