No one seems to have factored in the fact that this 'collapse the node plan' would be an all in strat by the UEF, and their fleet would likely be decimated, while many of the GTVA ships would still be in fighting form as they weren't just going gung ho for the node bleeding ships and lives.
As such, they could likely pursue decisive military victory WITHOUT having to nuke cities, and if anyone could push that win, Steele could. Earth builts its own gate now that the GTVA is in charge (if only with Steele as a proxy), GTVA victory.
The loss of life by this all in strat by the UEF would also likely be condemned by the Terran populace if all it did was hand Steele victory and kill a bunch of people, which would probably make it easier for Steele to take charge after victory