DAMASCUS — It is across an immense desert, between oil fields and Mesopotamian archeological sites overlooking the Euphrates, where Syria's future may be decided. The question, as Damascus makes more and more ground against ISIS and jihadists fighters, is the following: After seven years of a devastating war will the nation remain united? Or will Syria, once the guns fall silent, be lopped off from the northeastern territories now held by the pro-U.S. Kurdish troops?

Along the river that flows into neighboring Iraq, the Syrian army, together with its Russian and Iranian allies, is in direct confrontation with the Kurdish and Arab fighters of the U.S.-backed Syrian Democratic Forces (SDF) to retake the areas formerly controlled by ISIS. The last big battle is taking place in Abu Kamal, a town on the border with Iraq which jihadist fighters hidden in tunnels retook from Damascus on Nov. 11, just days after losing it.

But there's something much bigger at stake in these final desert battles. Three things in fact: What will be the future of Syrian Kurds, who aspire to a certain form of autonomy? What will become of the American bases that protect them? And, perhaps most crucial of all: Who will control the oil, the precious weapon for financing all sorts of ambitions?

In the living room of his home in Damascus' rebel-held neighborhood of Jobar, Naji Homsi unfolds the map of oil installations in this highly-coveted region. "Look at the pipelines," says Homsi, an oil expert, who's been unemployed since he left the city of Deir ez-Zor in 2013. "One goes west to Homs, the other towards Baniyas on the Mediterranean coast, another comes from Iraq."

The U.S.-backed SDF has retaken most of these wells from ISIS over the past few months. "But now that the Syrian regime is gaining ground, the American policy is focused on stopping Assad from retaking these wells," says an Arab nation's ambassador in Damascus.

In early October, the Syrian army got closer to the ISIS-held town of Conoco, home to the country's biggest gas fields, near Deir ez-Zor. But U.S. air strikes had already destroyed the operation room to prevent the jihadists from being able to use them. "Some $800 million invested by the Syrian government went up in smoke," a Damascus-based businessman quips with a resentful tone.

I accuse the Americans of having approved a deal between the Kurds and ISIS.

The latest episode in this desert war took place in late October around the al-Omar oil field, which boasted a capacity of 200,000 barrels per day before 2011. It is located near Deir ez-Zor, which Damascus retook from ISIS before the SDF, in early November. The Syrian troops were just three kilometers away from the jihadist-held al-Omar when the U.S. air force brought in SDF fighters from 45 kilometers away.

"I accuse the Americans of having approved a deal between the Kurds and ISIS," declares Nawaf Bashir, a tribal leader in Deir ez-Zor. "The Kurds let 400 jihadists leave Raqqa and travel to Abu Kamal and, in return, ISIS let the SDF take control of al-Omar. In just one hour, the pro-U.S. forces retook the field from ISIS without a fight." This also explains Russia's harsh criticisms, accusing Washington of "disrupting" anti-terrorist operations in this region. Especially given the fact that the SDF also took al-Jafra and oil fields, farther to the north, immediately after.

To counter Washington, Moscow is deploying hundreds of troops to guard oil installations recaptured from ISIS. These troops are in fact private mercenaries from Evro Polis, a company owned by an oligarch close to Vladimir Putin and ChVK Wagner, which recruits among former "volunteers' in Crimea. These henchmen are already operating near Palmyra, south of Deir ez-Zor, where they've started repairing strategic infrastructure. Time, indeed, is running out. Russian oil companies are already at work. Moscow wrested a deal from Assad according to which it's expected to make a clean sweep and operate most future oil production in Syria, leaving the mines, agriculture and certain refinery activities to the Iranians.

In these regions of northeastern Syria, populated with Arabs and Kurds, more and more Arabs have joined ranks with the Kurds, under U.S. pressure, to fight against ISIS. "Some 6,000 members of my tribe, the Baggara, fought against ISIS with the Kurds in Raqqa," Nawaf Bashir claims. "But when they see that the Kurds can control neither Raqqa nor Deir ez-Zor — the Arabs hate them — the members of my tribe will return to the Syrian government's fold."

Damascus is indeed trying to court them. Nawaf Bashir is one of the best prizes of war. In 2011, he joined the Syrian opposition exiled in Istanbul. "But I quickly realized that our agenda was being dictated from abroad, in particular by Qatar and its Muslim Brotherhood allies." In 2013, Bashir came back and knocked on the government's door. "It took me three years to get back in," he says. "Some people, here in Damascus, weren't for it." As a token for bringing him back in the fold, he offered 600 of his tribesmen to fight in Deir ez-Zor alongside Syrian troops and their allies, Lebanon's Hezbollah and the Iranians who are believed to have equipped them.

Who will the Arab tribes of Eastern Syria side with? "It's all about the money for them, they'll join whoever is the strongest," says Tareq Ahmad, a leader of the Homs province.

Damascus begins to appear as a solution, a lesser evil. "Look at Raqqa, nothing's happening there," Nawaf Bashir notes. About 80% of the city has been left destroyed by four months of airstrikes from the U.S.-led international coalition.

The International Committee of the Red Cross (ICRC) says the humanitarian situation is more critical than ever, with the number of refugees crammed in makeshift camps having risen from 90,000, to 300,000.

This is not reconstruction.

When he visited Raqqa after it was liberated from ISIS, U.S. Special Presidential Envoy for the Global Coalition to Counter ISIS, Brett H. McGurck, cautioned: "We are committed to stabilization, and that word is very important. This is not reconstruction." In other words, no money as long as Bashar al-Assad is in power.

Some loyalists believe that, when the time comes, Nawaf Bashir will be the man Damascus chooses to lead Raqqa. But the Americans and the Egyptians have another name in mind: Ahmad Jarba, a tribal leader from Eastern Syria and former leader of the opposition to Assad. "He's got money, he hoarded back then, when he was Saudi Prince Bandar bin Sultan's man," a Damascus-based journalist says.

"How long is the U.S. going to support the Kurds?" Robert Ford, the former U.S. ambassador to Damascus, recently asked. The Arab ambassador in Damascus says Washington must hold its position to counter the Iranians' progress in the region near the Iraqi border.

Meanwhile, in this multiethnic area, another threat is emerging: "If the Americans abandon the Kurds, in certain cities such as Hasakah, the Arabs could attack them," warns the aforementioned Syrian journalist, noting that Kurdish advances over the past few years were sometimes due to acts of violence against Arab civilians.

"The Kurds are taking land as a guarantee to reinforce their position at the negotiating table," Washington-based researcher Fabrice Balanche says.

The Kurds have astutely maintained friendships with both the Americans, who gave them weapons, as well as with the Russians, who are ready to grant them a certain autonomy in tomorrow's Syria. Under pressure from Moscow, the Syrian government has had to make some concessions. Some sources even mentioned an offer from Damascus to the Kurds, granting them limited autonomy in exchange for them liberating the Arab territories they now occupy in northeastern Syria. In short, the retreat of ISIS has left no one standing still.