Don’t be surprised by the downvotes. There seems to be a little bit of the “USA BAD” vibe here right now ~ especially in terms of the military. The US does seem to emphasize training and preparedness over simply having equipment which could lead to higher relative levels of contamination when compared to other militaries. I’m not sure if that is the case, but I recall the training differences being considered a factor when evaluating operational challenges (for example Saddam’s iraqi troops vs Cold War Soviets in the same equipment and situation ~ the Soviets would be expected to present a significantly harder challenge just by virtue of better training ~ at least in theory)

I guess if what you're saying is true, they can replace the foam with water or similar for the majority of training.

But that is the point of training - water is not foam. You have never used foam before if you used water for your foam training. You have no experience.

Maybe a substance with similar foamy propertoes but no pfas? Idk the answer

It might be a common problem to all air forces around the world but how many other countries have so many air bases around the world? I guess that no Japanese ever complained about the environmental impact of an Italian or French air force base in Okinawa.