It may be worth noting that the Hellfire Legion and Gallic Royal Navy are currently rep-hacked mutually hostile to each other. Creating an alliance with the GRN will thus be very challenging. At best you might come to some kind of mutual cease-fire in the presence of common enemies, but aiding each other is not really on the cards. Alternatively, if there was a unified request from Hellfire Legion players, the formal diplomatic stance between the HF and GRN could be revised.
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On the subject of this agreement; there seem to be growing concerns as to its implications. I feel obliged to point out that no player faction, official or otherwise, can prevent any other characters or player factions from accessing and fully utilising facilities belonging to their own NPC faction. That is, any character with a Hellfire Legion ID and IFF can utilise all Hellfire Legion bases without penalty or restriction - the same rule applies for all factions. Extrapolating from that, neither [HF] nor [D-W] have absolute authority over the Hellfire Legion NPC faction or over each other (as neither faction holds Official status, which would grant some authority as per Official Faction Rights). Wolf Squadron and Task Force Warhammer are separate entities, but both are operating under the general auspices of the Hellfire Legion, which is currently ruled by a council of Admirals - a NPC entity which may not be roleplayed by either player faction.