Damn, I only proposed to be surprised by some "amazing" plot twist that bewilders our petty prejudices, and suddenly and automatically I don't "get" plots, coz I'm just stupid like that. Of course I'm angry.
About your question is a far more pleasing and interesting one. Therefore I won't answer it.
No, really. It's a tough question. GTVA is on the higher ground now, so it's up to the UEF to show its own trump cards. It logically follows from the last cutscene that this trump card may have something to do with the Fedayeen, portrayed as a special group with special powers (like the spectres, say). More generally, they could theoretically resort to guerilla tactics and delay GTVA's victory as far as possible, since it's clear that bombing Earth is really out of the question.
However, they ought to be able to protect the council in any way, shape or form, and I'm both stunned at how is supposed the GTVA to strike them out, or UEF to protect them. IOW, I'm still somewhat at a loss where the black king in the chess board is supposed to be (something quite central to the game's strategy and tactics to be deployed, I'd say).
Now what particular trump card will the Fedayeen take out of their ass? Hard to predict, could be anything that crosses the minds of BP writers. A new stealth technology? A new fighter? Dunno.
GTVA? They still haven't used a lot of technical capabilities we might find in WiH2. Like tagging missiles, for instance, or the Pegasus. They showed brilliant schemes to wipe out ships in the first episode. I don't think we've seen it all. Their strategy should / could be heavily influenced / inspired by Delenda Est, to bring out timid UEF frigates & destroyers to the open so they can defeat them. Traps will be planned and tried to make. A mission outline where Laporte in a stealth fighter finds out about an incoming trap to a certain UEF battlegroup (and then further stress to get out fast to warn them... probably ending up in failure) feels possible.
Shivans are moddeled as if they were Shadows with their obscure psychological manipulations?
Vishnans haven't made an appearance in this universe yet. I have no idea where BP writers will take them.