Originally Posted by
BAengineer
As unlimited US access to LHR was the Jewel in the crown for the US Airlines in the Open Skies agreement I wouldn't bet against Trump pulling out of that agreement once the US lose that access through the UK no longer being part of the deal.
Then everyone is back to square one.
It might have been back then. However since then, US airlines have massively invested into point to point operation instead and nowadays serve pretty much every somewhat larger city in the EU directly. Which is enabled by the Open Skies agreement.