BEIRUT MUSEUM, LEBANON — BEIRUT'S museum area - for years the only crossing point between Christian east Beirut and the mainly Muslim, Syrian-controlled western quarters - has suddenly become a three-way crossroads where people can traverse the new battle line between warring Christian forces. A hundred yards east of the museum, people squeeze past a bus barricading a narrow side street and pick their way uphill into Ashrafieh, the heart of the Christian enclave. Behind a more serious barricade of containers, fighters from Samir Geagea's Lebanese Forces militia lounge in the sun, keeping vigilant for signs of impending attack by Gen. Michel Aoun's Army.
A similar distance to the south, the general's troops have settled into suburbs they captured from the militia two weeks ago in a battle that caused huge devastation.
Lebanon being Lebanon, the area between Christian militia and Army lines, and between the museum and west Beirut, has become a free trade zone where hundreds of enterprising vendors flock every day when there is no fighting. They sell everything you need to survive in a city at war with itself, where electricity and water supplies have been cut for over three weeks.
Grubby urchins from west Beirut dodge through the crowds, pushing carts laden with plastic containers of rare gasoline for Christian areas. From makeshift stalls and the backs of cars, traders hawk fresh fruit and vegetables, eggs, bread, bottled water, candles, and batteries. One man sells plastic sheeting and gaffer tape for the many whose house or car windows have been blown out. Everything going to embattled east Beirut must be carried, as one can no longer get in by car.
The old, ``traditional'' confrontation line has become a lifeline for the battling Christians. West Beirut, usually a byword for anarchy and violence, has become a haven. Many thousands of Christians have fled to the west, or crossed from other parts of the Christian enclave into Syrian-controlled areas up in the mountains. The Druze leader, Walid Jumblatt, has ordered his followers there to open up the hotels, treat the Christians kindly, and keep prices at normal levels.
West Beirut traders may be making good money by meeting the Christians' needs, but nobody is gloating at their misfortune. During the battles, staff in the Christian hospitals of east Beirut were deeply moved when nurses arrived from Muslim hospitals in the West with desperately needed medical supplies.
The old line has proved porous in other ways, too. When 200 of Mr. Geagea's fighters were trapped by the Army last week, they made a deal with the Syrian-backed Lebanese Army and militia factions in west Beirut, and slipped across the line into the southern suburbs. They were taken up to the port at the northern end of the line and allowed to cross back over into militia-held east Beirut.
In return, the Christian militia allowed the Lebanese Air Force's Hawker Hunter jets to be flown from the militia-controlled airstrip at Hallat, north of Beirut, to an airfield in Syrian-controlled territory.
Sources say the Syrians have also allowed fuel tankers to pass into areas controlled by Gen. Aoun's Army. The Syrians have done little to squeeze the general, who has felt free to pull troops from the battlefronts with the Syrians and send them against the militia.
``Syria wants both of us out,'' said militia leader Geagea in an interview at one of his bases in the area he controls north of Beirut. ``They want this to go on and on until both of us are finished, and they they'll come in with no Christian military or political power to face them. They will realize their dream by completely controlling the game here, as they do on the other side.''
Geagea admits he sent envoys to the Syrian-backed Christian president, Elias Hrawi, who is sitting impotently in west Beirut watching the battle between his rivals for the Christian leadership. ``Hrawi has nothing practical or serious to offer,'' the militia leader said. ``If he does not move now, what can he achieve later?''
The inter-Christian conflict has turned many other things upside down. When the civil war broke out in 1975, it was largely a battle between Christians and Palestinians. Now Yasser Arafat is sending envoys to try to mediate between the warring Christians. ``I thought I had seen everything,'' said a Lebanese observer.
Diplomats and many Lebanese observers fear the battle between Army and militia has yet to run its course. ``For General Aoun, anything short of total victory is defeat,'' said a senior diplomat.