 The French Army shifted its tactics at the end of 1958 from dependence on "quadrillage" to the use of mobile forces deployed on massive search-and-destroy missions against FLN strongholds.In 1959, Salan's successor, General Maurice Challe, appeared to have suppressed major rebel resistance, but political developments had already overtaken the French Army's successes.Recurrent cabinet crises focused attention on the inherent instability of the Fourth Republic and increased the misgivings of the army and of the pieds-noirs that the security of Algeria was being undermined by party politics.