By the summer of 1970, attention turned to the upcoming presidential election of August 17. Sulayman Franjiyah (also cited as Franjieh), who had the backing of the National Bloc Party and the center bloc in the Chamber of Deputies, was elected president by one vote over Ilyas Sarkis, head of the Central Bank, who had the support of the Shihabists (those favoring a strong executive with ties to the military). Franjiyah was more conservative than his predecessor, Hilu. A Maronite leader from northern Lebanon, he had a regional power base resulting from clan allegiance and a private militia. Although Franjiyah had a parochial outlook reflecting a lack of national and international experience, he was the choice of such persons as Kamal Jumblatt, who wanted a weaker president than Sarkis would have been. Franjiyah assumed office on September 23, 1970, and in the first few months of his term the general political atmosphere improved.

The expulsion of large numbers of Palestinian guerrillas from Jordan in late 1970 and 1971, as a result of severe clashes between the Jordanian army and the PLO, had serious repercussions for Lebanon, however. Many of the guerrillas entered Lebanon, seeing it as the most suitable base for launching raids against Israel. The guerrillas tended to ally themselves with existing leftist Lebanese organizations or to form various new leftist groups that received support from the Lebanese Muslim community and caused further splintering in the Lebanese body politic. Clashes between the Palestinians and Lebanese right-wing groups, as well as demonstrations on behalf of the guerrillas, occurred during the latter half of 1971. PLO head Arafat held discussions with leading Lebanese government figures, who sought to establish acceptable limits of guerrilla activity in Lebanon under the 1969 Cairo Agreement.

The Chamber of Deputies elections in April 1972 also were accompanied by violence. The high rate of inflation and unemployment, as well as guerrilla actions and retaliations, occasioned demonstrations, and the government declared martial law in some areas. The government attempted to quiet the unrest by taking legal action against the protesters, by initiating new social and economic programs, and by negotiating with the guerrilla groups. However, the pattern of guerrilla infiltration followed by Israeli counterattacks continued throughout the Franjiyah era. Israel retaliated for any incursion by guerrillas into Israeli territory and for any action anywhere against Israeli nationals. An Israeli incursion into southern Lebanon, for example, was made in retaliation for the massacre of Israeli Olympic athletes in Munich in September 1972. Of particular significance was an Israeli commando raid on Beirut on April 10, 1973, in which three leaders of the Palestinian Resistance Movement were assassinated. The army's inaction brought the immediate resignation of Prime Minister Saib Salam, a Sunni Muslim leader from Beirut.

In May armed clashes between the army and the guerrillas in Beirut spread to other parts of the country, resulting in the arrival of guerrilla reinforcements from Syria, the declaration of martial law, and a new secret agreement limiting guerrilla activity.

The October 1973 War overshadowed disagreements about the role of the guerrillas in Lebanon. Despite Lebanon's policy of noninvolvement, the war deeply affected the country's subsequent history. As the PLO's military influence in the south grew, so too did the disaffection of the Shia community that lived there, which was exposed to varying degrees of unsympathetic Lebanese control, indifferent or antipathetic PLO attitudes, and hostile Israeli actions. The Franjiyah government proved less and less able to deal with these rising tensions, and by the onset of the Civil War in April 1975, political fragmentation was accelerating.

Data as of December 1987