France crossed a catastrophic threshold in the Algerian war. [fact]
For the first time Frenchmen had fired upon, and killed, other Frenchmen; to the historically minded the dreadful spectre of the 1940s and, farther back, of 1871 presented itself. Across the breadth of France would echo the dying words of one of the Algiers gendarmerie lieutenants: “For two years I’ve been fighting against the fellagha. Now I’m dying at the hands of people who cry Algérie française! I don’t understand…!”
Horne, Alistair, A Savage War of Peace- Alge…, loc. 1100