Political timing gave the FLN respite from military pressure. [causal]
If de Gaulle could have followed up the momentum of his first weeks with a concerted peace drive, or if the Challe offensive had begun in 1958 instead of 1959, the prospects would have looked incomparably bleak. But, as it happened, the long build-up to the referendum and the November legislative elections, followed by the run-down from the paix des braves olive-branch, had given the F.L.N. an invaluable respite in which to regain its breath. And when in 1959 the A.L.N. was confronted with the gravest military threat to its existence, it was already moving in—and under—a new direction.
XREF: Counterfactual-dependent outcomes — the Algerian war's turning points hinged on electoral timing, echoing similar dynamics in Vietnam's Tet and US election cycles.
Horne, Alistair, A Savage War of Peace- Alge…, loc. 994