> The EU is free to pass laws preventing gatekeepers and insisting on interoperability requirements and Apple is free to refuse to do that and not offer their non-competitive gatekeeping products in the EU.
Apple is also free to lobby the US government and people to take action against the EU. Especially if Trump gets elected, Apple complaining about Europe taking advantage of American companies would resonate with a lot of the officials likely to staff such an administration.
Given Russia, it is likely that the US has far more leverage on the EU than the EU has on the US.