Go war Liberty over war debts and become even more debt riddled and Liberty takes over Bretonia like Gallia should have?
For an external thing, small or big, to me the logical step would be the Omegas. Bretonia did fine establishing Omega-3 as a necessary thing but who knows what else happens? Usually that leaves unlawfuls at disadvantage or leads to a house skirmish again. Not so sure if Brets want a border skirmish already?
Internal stuff is actually Dublin. I really wouldn't mind Mollys actually managing to threaten Bretonia's claim, a thing they didn't even manage during the Gallic invasion for real. Getting activity rolling in Dublin, with Gaians, some other unlawfuls and BHG to step in would be epic.
I would explain Dublin with Bretonia spreading thinly to protect its borders thoroughly, kind of a paranoid reaction to their neighbors having unclear intentions, Kusari still aims for Tau influence, Rheinland about to re-unite and no longer distracted by internal turmoil.
Edit: Just a late night thought coming from an overly tired brain