Oil was flowing through yellow hoses on the Safer’s deck to a newer, sturdier tanker moored alongside on a recent afternoon. Crew members took shelter from the punishing sun under tarps on the deck. Delicate operations to stabilize the oil tanks were still underway, but after so many ordeals — the failure of the Safer’s engine and other vital systems, the calamitous predictions that the ship could break apart or even explode — the worst of the danger seemed to have passed.

The United Nations, which led the rescue operation, announced late last week that virtually all the oil, amounting to some 42 million gallons, had been transferred off the Safer — an unexpected dose of good news for Yemen, which has suffered through a protracted civil war and a devastating humanitarian crisis.

The conflict has killed tens of thousands of people since 2014 and divided the country between rival authorities, making the kind of negotiations the rescue operation required both arduous and exceedingly rare.

The Safer contained roughly four times the amount of crude oil that spilled from the Exxon Valdez into Alaska’s Prince William Sound in 1989. The transfer of the crude “prevented what could have been an environmental and humanitarian catastrophe on a colossal scale,” U.N. Secretary General António Guterres said in a statement.

For years, efforts to neutralize the threat from the Safer had come up empty — because of the war, disagreements over how the oil should be secured and struggles to raise funding. A renewed effort in 2020 proposed to transfer the oil off the ship to another tanker, rather than securing it in place.

The complex initiative required the purchase of an oil tanker, the hiring of a salvage company and coordination between bitter foes on opposite sides of Yemen’s conflict. A Yemeni businessman, Fathi Fahem, played a pivotal role, helping to mediate between the United Nations and the Houthis, the Iranian-backed militant group that rules northern Yemen.

“I don’t know what happened between them, but the trust was zero,” Fahem said in an interview.

Despite the success of the operation, fears remain that the transfer of the oil could provoke a fresh set of arguments: over who owns the crude, which party should profit from its export and whether the replacement tanker — called the Yemen (formerly the Nautica) — will become a new bargaining chip for the Houthis. A shaky truce has held for more than a year, but the country is still at war, its divisions more entrenched than ever.

U.N. officials have downplayed those concerns, focusing on the long odds they overcame since the oil transfer started in late July.

“Skepticism was extremely high,” said David Gressly, the U.N. resident and humanitarian coordinator for Yemen. “It is at least an indication that an agreement can be reached and carried through.”

“It’s good to have a bit of a win in a country that doesn’t see that very often,” he added.

The Safer was launched in 1976. About a decade later, it was converted into a floating oil storage and offloading vessel, or FSO, and connected to an oil pipeline in Yemen. Maintenance on the vessel stopped in 2015 after the Houthis deposed Yemen’s government and began consolidating their grip on the north of the country.

The rival, internationally recognized government, which is backed by Saudi Arabia, is headquartered in the southern city of Aden.

In 2018, the Houthis began raising alarms about the possibility of an explosion or an oil spill from the tanker, even as they initially denied outsiders access to the vessel. Its position in the Red Sea, a few miles from the port city of Hodeida, made it a threat to the import of food and other humanitarian supplies, as well as to fisheries, coral reefs and marine mammals.

In the event of a disaster, worst-case scenarios modeled by experts predicted drastic spikes in fuel and food prices; the exposure of millions of people to harmful pollutants; and the loss of hundreds of square miles of agricultural land.

In 2020, water leaked into the engine room, which could have resulted “in a catastrophe,” Gressly said. Local crew members and divers were able to secure the leak using rudimentary steel plates, he said.

Ibrahim Sharafeddin Al-Mawshiki, a member of a committee that managed the Safer rescue for the Houthi-led government, said the Houthis had consistently cooperated with the United Nations to find a solution to the threat. He blamed the tanker’s decay on a sea and air blockade imposed on Yemen by a Saudi-led military coalition.

Fahem worried about the potential ecological damage, but also the threat to his family business, the Fahem Group, which imports wheat and maintains grain silos in the Red Sea port of Al-Salif, near the Safer. He became involved in efforts to save the tanker in 2020, partly out of frustration that earlier initiatives were going nowhere.

“We had an interest to protect our future investment,” he said.

The only solution was to “replace the old tanker with a new one,” he said. A Dutch salvage company, SMIT Salvage, was identified to prepare the Safer for the oil transfer. “It took a while to convince them to come to Yemen. It wasn’t easy,” Fahem said. The Houthis insisted on Fahem’s personal guarantees, including his assurance that the United Nations would deliver a mooring device, known as a CALM Buoy, to secure the replacement tanker.

Fahem was one of the signatories to a memorandum of understanding in March 2022 that committed the United Nations to securing a replacement tanker. “I was put in the middle from the beginning to the end,” he said. “The whole process was really difficult.”

The United Nations faced steep challenges as well, including raising $120 million to fund the operation. A replacement tanker had to be purchased, and response equipment positioned should a spill occur, said Mohammed S. Mudawi, the U.N. project manager. There was a time crunch too, given that winds and high waves would pick up beginning in September, making it more difficult to secure the tankers.

For the salvage crew, the work was grueling, Mudawi said during an interview in Hodeida.

Temperatures on deck could reach more than 120 degrees. “Those on the day shift really struggle,” Mudawi said. At least one member of the Dutch salvage team was forced to go home after a week of work, he said.

And the work is not yet done. Crews are still cleaning residual oil from the tanks so the ship can be sold for scrap. U.N. officials hope the tanker parts could fetch about $20 million and contribute to the costs of the rescue operation.

But Al-Mawshiki of the Houthi committee cast doubt on the recycling plan, saying in an interview that “what we agreed is that the Safer is going to remain where it is” — a sign of possible disagreements that could surface during the next phase of the operation.

Those arguments could extend to who profits from the crude, the majority of which is state-owned, including by an oil company that is now divided between the Houthis and the government in Aden.

Fahem said the question of ownership was left to the side on purpose.

“We focused on getting the oil as soon as possible to the replacement tanker. And then we have all the time in the world to look at who the oil belongs to.”

The oil, he added, “is supposed to belong to Yemen.”

Gressly, the U.N. coordinator, said some of the disputes would only be resolved with a peace agreement. But that was a problem for another day.

“The oil is not going to collapse into the ocean in six months’ time,” he said. “Let’s hang on to that.”