Nonetheless, I anticipate teething problems, including some form of malicious compliance. The latter of which the EU tends to take a dim view.
One could also argue that if it takes longer than 6 months to add something dictated by law, you simply have to implement it faster or accept the consequences.
I don't think companies this big has a lot of excuses for taking so long to implement things. They have thousands of employees they can shift from other projects (projects that doesn't decide if the phone is illegal or not) to implement urgent things like this.
Then that will increase the implementation cost by at least (edit: up to) 10% of their global revenue.
Assuming they won't go with the maximum amount early on.
The US military having bases in Europe is a mutually beneficial arrangement, not some sort of charity America is giving Europe. The US threatening to withdraw from those bases for the sake of Apple would be supreme stupidity. Not impossible, but supremely stupid. There are much bigger fish in this sea than a handful of tech companies, large as they are. Apple is a small drop in the bucket compared to the vast commercial and industrial scope of America's global priorities.