Here we go again. I am from the US and fly within the US, seldom to Canada. The legal difference between European States and states within the US is fairly obvious. However, I have some sympathy for European (British etc) pilots' resentment toward the operational reality regarding US airlines which fly cargo etc within Europe, especially on bread-and-butter routes, and the protections in place here against cabotage.
On the other hand, if one's US company says: there will be a 727 base in Paris (i.e. FEDEX), and if senior pilots do not bid to be based there, it will be assigned to and forced upon junior 727 pilots-you must go or lose your job, in theory and reality. One of our FOs flew in his previous job as a DC-8 FO for Emery (based in Ohio). They had some two-day layovers in Brussels, which he really enjoyed. They also operated into Spain or whereever else.
Why did the European associations, or whatever they are called, allow this? Was it trade pressure from the US?