Geagea announced his decision on Monday during a press conference, calling on his allies to endorse his rival in an effort to move the country forward.

"I announce after much studying and thought...that we have adopted the candidacy of General Michel Aoun for presidency in a move that carries hope of getting out of our situation toward a more secure and stable life," Geagea said.

Aoun, an 80-year-old ex-army commander, still needs the support of Lebanon's parliament. While he's a strong ally of the Shiite Hezbollah terrorist organization, Aoun also has many enemies within the country's government.

Fractious politics

Lebanese politics have been stuck in a quagmire since May 2014, as the country has been unable to fill the empty seat for president, which is reserved for a Christian candidate. Sunni Prime Minister Saad Hariri angered both Geagea and Aoun last year when he nominated a candidate without consulting them.

Until now, Geagea has been staunchly opposed to Aoun's candidacy, a factor that led to stalled negotiations over the past 20 months.

Geagea's move is all the more surprising because he fought against Aoun's forces during the civil war that divided the country in the 80's and 90's.

blc/kms (AP, AFP)