The FedEx LOA (discussed on several threads from different prospectives) has not been seriously contemplated from a WCS (worst case scenario )
What can FedEx do, and more importantly, what will it do if the LOA is defeated by the FedEx pilots and the company refuses to improve or renegotiate the terms??

Hire Foreign pilots
This would be the major fear of most FedEx pilots. It would affect junior pilots hard and poolie and FedEx wanna be pilots the hardest. Is it a reasonable fear??
IMHO, for a Paris crew base, yes. If FedEx can legally (via our CBA and whatever courts would hear a (supposed lawsuit) hire pilots outside our working agreement, they could reasonably expect to find qualified pilots within Europe willing to leave other less desirable airlines (Ryanair, Easyjet, etc) to fly for FedEx for what FedEx has offered us. The downside: Labor laws and other work issues. Incompatible work groups (different FedEx pilots flying under different ops specs and different national laws (JAA vs FAR). Crews can't (and wouldn't want to) fly together, disallowing scheduling synergies. Cost of duplicate flight managements and other associated staff functions duplicated. With a small pilots group without much time or personal investment in job, an increased risk that even captains would leave for greener pastures, should opportunities present themselves. A small crew force would be more greatly affected by small changes in staffing. Two pilots leaving on short notice would be a bigger issue than within (our) current 4800+ pilot group. A much increased risk of (successful ) job action owing to cultural differences and more favorable labor laws (especially in France). Last and not least, the negative affect such an action would have on the morale and disposition of US based FedEx pilots. Cooperation, "Fuel Sense", labor peace?? Out the window.
Hong Kong. Even less likely to prove successful. Why?? look at the situation on the ground in both the main land (China) and HKG. Chinese airlines are growing by leaps and bounds, so much so they cannot hire enough local talent to fill the slots they have now. The Chinese are as protective, if not more so, than anyone in trying to keep what they see as local jobs for the local team. They are so desperately short they are hiring westerners to fly for their national airlines.
In Hong Kong the main carrier (Cathay) and its sister airline, Dragon air are either hiring or have (some) better terms than FedEx is offering. FedEx would have to compete with a very desirable airline in its own right for pilots willing to live and work in HKG. In reading comments from Cathay pilots on another forum, they are unhappy with several aspects of their working conditions, but in reading their woes, I don't think FedEx would be offering anything that would cause a mass exodus from Cathay (maybe Dragon, but would have to hear from better sources to believe so). The cost of living in HKG is higher than Paris, and unlike Paris, you can't as easily get away from it. Its is also interesting to note that Cathay bases many of its pilots outside of HKG, presumably because of the problem of retaining qualified crews and HKG QOL, FedEx would be competing for the scarce labor willing to work in HKG. HKG is an island, in both the literal and political sense. Living in mainland China may not be an option, even if you wanted to. QOL in HKG is going to require money, more so than it appears the company is willing to fork out. And like Paris, lack of school redemptions will limit interest to very young families or older pilots without school age children. Finally, regarding interest in HKG, I think less pilots will be interested in doing a two year or longer tour in the fragrant city (HKG) than they would Paris. From my experience, most pilots enjoy the HKG layover, but by day 4 they are ready for a change. It would be different living there for sure, in some ways better, but it will still be the crowded place we know from short visits. Again like a European base, hiring pilots and keeping pilots will be a constant battle I think the company doesn't want to get itself involved in.
In closing, could they do an end run around the FedEx pilot group and staff non US based pilots?? Probably yes. Would they be willing to?? Only those at the highest level know the answer. I think it wouldn't take a whole more to make going to either Paris or Hong Kong a reasonable proposition for FedEx families willing to entertain the option. Certainly it will be less than the cost (to FedEx) of going the WCS way.