By Tom Perry
BEIRUT (Reuters) - Lebanese Christian politician Samir Geagea backed his rival Michel Aoun for the presidency on Monday, reshaping Lebanese politics in an apparent break with his Saudi-backed allies that aligns him with a civil war era enemy supported by Hezbollah.
The surprise announcement edges 80-year-old Aoun closer to the presidency, vacant for 20 months, and marks a rare show of unity in a Christian community riven by divisions for decades.
But he must still secure wider backing to secure the position reserved for a Maronite Christian in Lebanon's sectarian political system.
Geagea and Aoun, who fought each other in the 1975-90 civil war, have been on opposite sides of Lebanon's political divide since Syrian forces withdrew from Lebanon in 2005.
Aoun is part of the March 8 alliance dominated by the Iranian-backed Shi'ite group Hezbollah. Geagea is part of the March 14 alliance led by Sunni politician Saad al-Hariri, who is in turn backed by Saudi Arabia.
Sitting with Aoun at a news conference, Geagea said the move was intended to rescue Lebanon from political crisis. The government barely functions, paralyzed by rivalries exacerbated by regional conflict.
Geagea said the step "carried hope of getting out of the situation we are in, to a situation that is more secure, more stable - a normal life". Lebanon was on the verge of the abyss, requiring "an unusual rescue operation, regardless of the price", said Geagea, who himself covets the presidency.
The rapprochement may kill off a proposal by Hariri that nominated another Maronite, Suleiman Franjieh, for the presidency in a power-sharing proposal that would have made him prime minister. Both Geagea and Aoun opposed that initiative which was backed by both Iran and Saudi Arabia.
Geagea had been the official presidential candidate of the March 14 alliance until Hariri tabled Franjieh - part of March 8 - as an alternative. Though Franjieh has close ties to Hezbollah, the group has stuck by Aoun.
Geagea called on his March 14 allies to back Aoun after reading a joint declaration that called for a new parliamentary election law and an "independent foreign policy" while declaring Israel an enemy - an important consideration for Hezbollah.
Aoun said the "black page" of the past was over and "must be burnt". "We must leave the past in order to build a future," he said in the conference at Geagea's home in Maarab in mountains overlooking the Christian town of Jounieh.
"MARCH 14" TO BREAK UP ?
The Lebanese parliament elects the president, and a two-thirds quorum is required for the vote to go ahead. Even with Geagea's backing, Aoun and his existing allies do not have enough sway to secure his election.
More importantly, Parliament Speaker Nabih Berri, a powerful Shi'ite politician who heads the Amal Movement and is also part of March 8, has said he will not call parliament to elect a president unless all the main sectarian parties attend.
That means Aoun must win Sunni backing in addition to the strong Shi'ite support he enjoys from Hezbollah.
An MP in Hariri's Future Movement, Mohamed Kabara, signaled discord over the declaration, saying "partnership is not about arm twisting, or imposition".
Nabil Boumonsef, a commentator in the an-Nahar newspaper said it marked a big change in the Christian and Lebanese political landscapes. "The biggest result will be the break up of March 14 as a result of this landscape," he said.
The March 14 alliance was forged in 2005 from groups opposed to Syrian influence over Lebanon, and enjoyed great support from the U.S. administration of President George W. Bush, in addition to Hariri's backers in Saudi Arabia.
Tensions between March 8 and March 14, particularly over the question of Hezbollah's arsenal, spilled into a brief civil war in 2008. Hezbollah has since deployed fighters to Syria where it is battling alongside President Bashar al-Assad's government.
The Aoun-Geagea struggle in the civil war was known as "the war of elimination". Aoun's Lebanese army loyalists and Geagea's militiamen fought fierce battles in the Christian enclave in early 1990, months before Syrian-led forces drove Aoun into exile, ending the country's civil war.
Both were forced out of public life in the period of Syrian dominance that followed the civil war. Aoun lived in exile in France, and Geagea was imprisoned, the only Lebanese civil war leader to pay a judicial price for his actions in the conflict.
Geagea was released and Aoun returned in 2005, when Syria was forced to pull its troops out of Lebanon after the assassination of statesman Rafik al-Hariri.
(Additional reporting by Laila Bassam and Mariam Karouny; Editing by Richard Balmforth)