Ultra leaders' desperation blinded them to mainland French power. [causal]
Ortiz aimed, immediately, for a replay of 13 May 1958, but this time ending with a total and irreversible victory for the pieds noirs. … Once again there was no thought in the despairing minds of the “ultras” of “what then?” Nothing revealed better the egoistic isolationism of their despair and the unreal world which it drove them to inhabit than Susini’s wild declaration at this time: “The irreversible process is now under way. Between the republic and Algeria, we choose Algérie française!” Characteristically, the possible reaction of fifty million metropolitan Frenchmen was simply not taken into account.
XREF: Fits the author's broader pattern of depicting the pieds noirs' siege mentality and isolationism across the Algerian crisis.
Horne, Alistair, A Savage War of Peace- Alge…, loc. 1092