Doing that would mean acting in bad faith (obviously) but also breaking WTO Rules, i.e. international law, which can come with a big price tag if your caught (potentially unlikely in such a scenario and depends on the WTO being accepted by the US, which is also not very likely). That is on top of being sued by Boeing in Court for wrongfully denying the recertification. So I'm not sure whether that would really be a consideration.

Well there was the whole 300% tax on Bombardier debacle, boeing got them punished without even having a competing aircraft!

https://money.cnn.com/2017/10/06/news/companies/boeing-bomba...

Well, they drove Bombardier CSeries (a small barely competing program with some potential) into the hands of Airbus (a huge threat with production and logistics capabilities) for free. In the end USA won (they got production of new aircraft on their soil). Boeing? A total loss.

> It's a great way to screw over Boeing (American) and boost sales for Airbus (EU), while having the fairly legit rationale that you no longer have confidence in the US regulator due to a long series of blunders

Trade agreements are written to anticipate this sort of thing.

Such a decision would also screw over EU airlines that still depend heavily on Boeing.

You must be a real gem to work with