The FLN uprising presented nationalist groups with the question of whether to adopt armed revolt as the main course of action. During the first year of the war, Ferhat Abbas's Democratic Union of the Algerian Manifesto (UDMA), the ulema, and the Algerian Communist Party (PCA) maintained a friendly neutrality toward the FLN. The communists, who had made no move to cooperate in the uprising at the start, later tried to infiltrate the FLN, but FLN leaders publicly repudiated the support of the party. In April 1956, Abbas flew to Cairo, where he formally joined the FLN. This action brought in many volus who had supported the UDMA in the past. The AUMA also threw the full weight of its prestige behind the FLN. Bendjelloul and the pro-integrationist moderates had already abandoned their efforts to mediate between the French and the rebels.
After the collapse of the MTLD, the veteran nationalist Messali Hadj formed the leftist Mouvement National Algrien (MNA), which advocated a policy of violent revolution and total independence similar to that of the FLN, but aimed to compete with that organisation. The Arme de Libration Nationale (ALN), the military wing of the FLN, subsequently wiped out the MNA guerrilla operation in Algeria, and Messali Hadj's movement lost what little influence it had had there. However, the MNA retained the support of many Algerian workers in France through the Union Syndicale des Travailleurs Algriens (the Union of Algerian Workers). The FLN also established a strong organization in France to oppose the MNA. The "Caf wars", resulting in nearly 5,000 deaths, were waged in France between the two rebel groups throughout the years of the War of Independence.
On the political front, the FLN worked to persuadeand to coercethe Algerian masses to support the aims of the independence movement through contributions. FLN-influenced labor unions, professional associations, and students' and women's organizations were created to lead opinion in diverse segments of the population, but here too, violent coercion was widely used. Frantz Fanon, a psychiatrist from Martinique who became the FLN's leading political theorist, provided a sophisticated intellectual justification for the use of violence in achieving national liberation. From Cairo, Ahmed Ben Bella ordered the liquidation of potential interlocuteurs valables, those independent representatives of the Muslim community acceptable to the French through whom a compromise or reforms within the system might be achieved.
As the FLN campaign of influence spread through the countryside, many European farmers in the interior (called Pieds-Noirs), many of whom lived on lands taken from Muslim communities during the nineteenth century, sold their holdings and sought refuge in Algiers and other Algerian cities. After a series of bloody, random massacres and bombings by Muslim Algerians in several towns and cities, the French Pieds-Noirs and urban French population began to demand that the French government engage in sterner countermeasures, including the proclamation of a state of emergency, capital punishment for political crimes, denunciation of all separatists, and most ominously, a call for 'tit-for-tat' reprisal operations by police, military, and para-military forces. Colon vigilante units, whose unauthorized activities were conducted with the passive cooperation of police authorities, carried out ratonnades (literally, rat-hunts, raton being a racist term for denigrating Muslim Algerians) against suspected FLN members of the Muslim community.
By 1955, effective political action groups within the Algerian colonial community succeeded in convincing many of the governors general sent by Paris that the military was not the way to resolve the conflict. A major success was the conversion of Jacques Soustelle, who went to Algeria as governor general in January 1955 determined to restore peace. Soustelle, a one-time leftist and by 1955 an ardent Gaullist, began an ambitious reform program (the Soustelle Plan) aimed at improving economic conditions among the Muslim population.