Tripoli, Lebanon — The sun burned brightly. The Mediterranean sparkled. And the guns of Tripoli, site of the Palestinian civil war this month, slept almost silent. Only the occasional rifle shot, a couple every three or four hours, competed with honking horns and sidewalk chatter in Lebanon's second largest city. How long the calm will last is anybody's guess.
But as a cease-fire between Palestinian leader Yasser Arafat and his Syrian-supported rival guerrillas continued to hold through sundown Tuesday, this ancient city looked as if the artillery, rocket, and gunfire had quieted weeks, not merely days, ago.
Near Mr. Arafat's headquarters, sidewalk vendors peddled grilled cheese sandwiches and spicy Arabic coffee to young guerrillas, foreign reporters, and the occasional local passer-by. A loudspeaker truck hailed not military orders, but prices for big ripe tangerines.
A girl about 10 years old watched the scene with wide friendly eyes and cradled a plastic toy rifle in imitation of the real thing toted by nearby Arafat loyalists.
''M-16. A good rifle. Made in America,'' one of the real guerrillas remarked jokingly of his own weapon. Mostly, the Palestinians displayed Soviet, AK-47 rifles with their distinctive, banana-shaped handgrips.
An Arafat spokesman adopted a suddenly serious tone: ''The Syrians,'' he said , ''have brought up new quantities of tanks'' around the city.
The Syrians, themselves, were in fact not in evidence in the anti-Arafat positions above and inland from the Palestinian chief's headquarters. There were , however, men from the Palestine Liberation Army, a nominally independent force integrated in the Syrian Army. At roadblocks, atop the occasional armored personnel carrier, anti-Arafat forces looked relaxed as they walked along the roads climbing upward from Tripoli. If their tank numbers had indeed been reinforced, evidence of this was not visible.
''Damascus says we should not shoot,'' said one youth. As long as that goes, he said, the cease-fire holds.
Meanwhile, a war of guns has given way to a war of nerves. The issue is how, if, or when Arafat will leave Tripoli as part of a disengagement with his rivals.
Arafat, on the defensive less than a week ago, now exudes new-found confidence. Smiling and jaunty as he enters his white Jeep, he makes it clear he is not exactly in a hurry to leave. Other Arafat loyalists add that they think Syrian President Hafez Assad's recent illness may be more serious than officially reported and that this gives them more room in dealing with the Syrians.
''Arafat doesn't sound as if he is going to leave, at least not soon,'' remarked one rival at a hillside position some two miles inland from the Palestine Liberation Organization chief's headquarters. ''And if he does not, then sooner or later, there will be more fighting.''
Arafat's chief Lebanese militia allies in Tripoli - a fundamentalist Muslim organization - present a slightly less simple picture of the situation, however.
In one of Lebanon's ironies of history, the group's prized outpost is a Christian crusader castle on a steep rise near the center of town. Until they late 1960s, it housed a restaurant and a theater for tourists. Since the outbreak of Lebanon's civil war in 1975, the site has been occupied in turn by various military forces.
''Just as in the crusader days, it is the best position,'' explains a handsome, black-bearded Islamic militia officer who goes by the name Abu Muhammad. ''When the Syrians shell, these thick stone walls can take it . . . and it is a commanding location.''
''We would prefer it to be a restaurant again,'' he says. ''But first, we must defend ourselves.''
''Arafat will leave,'' the man says a bit later. Even though the PLO leader hints at staying put, ''the Syrian's have Tripoli surrounded. . . . He will have to go.''
After a pause, he adds: ''God will compensate. Through God we shall have our revenge. After Tripoli, there will be a large war between Syria and Israel. . . .''
On the road back to Beirut after nightfall, shellfire suddenly erupted from Druze positions in the inland hills on the outskirts of the capital. It offered a reminder that other conflicts still simmer in Lebanon. Three rockets flashed toward Druze positions in apparent counterfire.
Motorists heading for dinner or a movie began screeching homeward. Lebanese Army regulars manning checkpoints that usually slow vehicles for at least a cursory glance inside, energetically waved through all comers in deference to the most serious such flare-up since a cease-fire in September.