FACTBOX: Conflict or concessions: scenarios for Lebanon

(Reuters) - Lebanon's worst internal crisis since the 1975-90 civil war escalated sharply this week when the U.S.-backed government took decisions aimed at Hezbollah that the pro-Iranian group viewed as a declaration of war.

Following are scenarios for how the conflict may unfold:

CONFRONTATION

The government refuses to give in to Hezbollah's demands. The group also refuses to back down. Lebanon will face more confrontation.

* Armed conflict

- Hezbollah leader Sayyed Hassan Nasrallah on May 8 said in public for the first time that the group was prepared to use its guns against domestic foes in the face of a threat to its arsenal. Armed clashes between Hezbollah, backed by gunmen from allied factions, and fighters loyal to the governing coalition could continue. Hezbollah's military dominance is not disputed. The strength of pro-government factions is not clear. Most analysts have ruled out the idea of a full-scale civil war because of Hezbollah's military dominance. But tensions between the sides, the depth of animosity between their followers and the ready availability of guns mean that armed clashes could go on for some time.

* Hezbollah keeps grip on roads, airport remains largely paralyzed

- Hezbollah will likely maintain its grip on Beirut's roads, effectively shutting the airport. The group and its opposition allies could call on followers employed by the state to stop going to work, further weakening institutions of government. Hezbollah could move to take physical control of government buildings. On May 9 it forced pro-government Beirut TV off air. But a move to storm the main government headquarters occupied by Prime Minister Fouad Siniora is seen as unlikely. Despite its military dominance, Hezbollah is very unlikely to attempt a full takeover of government in the manner that Hamas secured control of the Gaza Strip in 2007. Hezbollah's Nasrallah has said the group will not use its weapons to bring about a change of government.

* Government stays in office  Continued...