Work continued through the night, lit only by the beams of headlights and a single construction light, to replace a bridge collapsed by an Israeli air strike, across the Litani river.
But when dawn broke Thursday over the green waters, those Lebanese Army engineers withdrew, so that a convoy of trucks packed with hundreds of soldiers could begin reinforcing a cease-fire, and deploying across south Lebanon for the first time in some 40 years.
"Go, go, go!" shouted one officer, directing traffic as vehicles flying Lebanese flags crossed the metal span one at a time.
With a quiet confidence, despite wearing paint-chipped metal hats for helmets, in some cases, and other aging gear – these soldiers hope to turn a symbolic moment into a historic one.
This vanguard force of 2,000 is to help solidify the cease-fire after a five-week war, and guarantee that the Israeli forces withdraw from Lebanon and that Hizbullah fighters shift their weapons north of the Litani, or keep them out of sight.
"This war is finished," says a United Nations official. "When you have the political will [on both sides], it takes only one man to guard the border – it is enough."
But no force was strong enough to prevent the Israeli bombardment that pulverized scores of Lebanese villages, thousands of homes, and swaths of Beirut; nor the nearly 4,000 rockets fired by Hizbullah into northern Israel. While both sides have reasons to stop – Israeli Prime Minister Ehud Olmert and his top brass are fighting for their political lives to justify their actions, and Hizbullah leaders need to finally ease the pain for 900,000 affected Shiite civilians – lasting peace is uncertain.
The UN Security Council is still determining the new robust rules under which an expanded UN force – from 2,000 to 15,000 international troops in the coming weeks – will work alongside the 15,000 Lebanese Army soldiers now beginning to deploy.
"Old UNIFIL is dead, and New UNIFIL will be stronger, enhanced with more people, and above all with new rules of engagement," Alain Pellegrini, the French UN force commander, told reporters on Thursday.
But those rules remain "under consideration; they are not defined," says General Pellegrini. Whether Hizbullah will be disarmed, and how, depends on a Lebanese government decision. But the uncertainties are complicating efforts to find new UN troops.
Could the UN confiscate Hizbullah weapons that it finds? Could it be asked to disarm the small guerrilla force that just fought Israel's vast military machine to a standstill, yet continue to fire rockets across the border?
"Contributing countries need to have some assurances about ... the conditions, the rules, the task," says Pellegrini. "No country can decide to put soldiers here without any guarantees."
Amid questions of Hizbullah's intent, officials sought to reassure fellow members of the Lebanese government – as well as potential donors of UN troops – that Hizbullah was not looking for a further fight.
"There will be no confrontation between the Army and brothers in Hizbullah," said Information Minister Ghazi Aridi, after the Lebanese cabinet decided Wednesday to deploy its troops across the south. The Army would not "chase" Hizbullah, he said. "There will be no authority or weapons other than those of the state. If any weapons are found, even the brothers in Hizbullah have said 'let it be in the hands of the Army, no problem.' "
Israel says that its forces – which peaked last weekend at 30,000 inside Lebanon – have pulled out of half the territory they occupied. As the Lebanese Army moved south, they were greeted in some places with crowds throwing flowers and praying for peace.
A Lebanese troop transport ship docked in the southern port city of Tyre, unloading hundreds of troops and their American-supplied armored personnel carriers. Some had small Lebanese flags sewed to their backpacks. "We are doing our nation's duty," said Kamel Zaiyoun, a young man jammed in the back of a truck with other soldiers. "We are very happy to protect our country. Hopefully, there will be no more war."
"We feel so proud, so great to defend our country," says one officer nearby. With their Lebanese Army presence end the war? He shrugged, but would not answer. Those answering a resounding "yes," though, are the 250,000 people the UN says have already returned to the ruin of the south.
Many have mattresses bound to the roofs, ready to camp if their homes are beyond immediate repair. At one crossing on the highway south from Beirut, four lanes of traffic funneled into one, and men pushed cars over a berm of rubble, providing a snapshot of the mosaic of Lebanon.
Here large families crammed into generation-old, Mercedes cars, laden to bursting with the worst of the road to come; clerics road in the back seats of slick black Mercedes; some came home by Syrian buses.
Some cars have posters of Hizbullah leader Sayyed Hassan Nasrallah. Soldiers wearing camouflage drove south to their units. And one man wore his patriotism on his skin – an illustration of how hard peace between Lebanon and Israel may be.
Tattooed across Bassam Sabra's right forearm are the words "Love," and "Freedom," in English with a statue of liberty–style arm holding a torch. On his left forearm is a broad cedar tree for Lebanon, with the number 10,452, the total square kilometers that make–up his Lebanon.
Further up that arm at the shoulder is another tattoo, "We born free."
But Mr. Sabra who has spent one–and–a–half years in an Israeli jail, has yet another tattoo: a star of David, symbol of Israel, on the sole of his foot.
• Wire reports were used in this report.