GAZIANTEP, Turkey—When Donald Trump sits down with Vladimir Putin in Hamburg Friday, he’ll be taking an unusual posture for a big-time dealmaker—that of the suppliant, begging Russia to solve the Mideast’s biggest problem.

The Syria war, now in its seventh year, has generated dangerous tensions in the region and beyond. It’s divided the NATO alliance, produced the world’s biggest refugee crisis and could still lead to a regional war. But so many international players are now involved—each with its own agenda, many with enough chips on the table to veto the others—that Putin alone cannot solve it.

There’s clearly growing acceptance of the Russian position that, at least for now, Syrian President Bashar al-Assad will remain in place while everyone (it is hoped) focuses on fighting the so-called Islamic State.

Recently elected French President Emmanuel Macron has made that explicit, even though France previously led the way demanding Assad’s removal. And the Trump administration has expected the relevant actors to read between its lines: “Of course that’s our policy,” one senior White House official told The Daily Beast’s Spencer Ackerman on Thursday. “I don’t see how you could follow what we’ve done and not come away with [that] conclusion.”

U.S. Secretary of State Rex Tillerson publicly laid out a new U.S. proposal intended to “produce stability” in Syria as he departed Wednesday en route to the G-20 summit where Trump and Putin are due to meet. It calls for no-fly zones in Syria and cease-fire observers on the ground, with the implication that they will include Americans and Russians.

Tillerson also called for “coordinated delivery” of humanitarian assistance, which up to now has been blocked by the Assad regime. And he asked for assurances that territory the U.S. is helping liberate from Islamic State extremists will not fall “illegitimately” into the hands of any faction in Syria.

Tillerson didn’t spell out which factions, but he may have been referring to the scramble on the ground during the current battle for Raqqa, the capital of the ISIS “Caliphate.”

Even as the U.S. conducts airstrikes in support of Kurdish-led ground units ousting ISIS, Assad regime forces and Iranian-led Shiite militias have been advancing toward Raqqa, with the apparent goal of seizing territory as it is freed. They’ve also been moving toward Deir al-Zour, the oil-rich region under ISIS control, where the U.S.-led coalition has been carrying out extensive airstrikes against ISIS targets.

But Tillerson did not address the central question of Syria’s future: the fate of Bashar al-Assad, who went to war against his own people rather than respond to demands for reform of his dictatorship in the 2011 national uprising. As many as 400,000 have died in the fighting, 6 million have fled the country, and 4 to 5 million are displaced within it.

Even so, at a meeting with UN Secretary General António Guterres last week, Tillerson is reported to have said that Assad’s fate is in Russian hands.

It isn’t so simple.

Even if Russia agreed to replace Assad, it can’t necessarily deliver. Russian air intervention has dramatically changed the balance in Syria, reducing the area controlled by anti-government rebels from over 60 percent to under 20.

But the ground forces that have seized most of the gains are Iranian-commanded militias, many with foreign fighters from Lebanese Hezbollah, Iraq, Afghanistan, Pakistan, and other countries. So Iran, whose Revolutionary Guard has poured resources into the fight for more than three years and passionately backs Assad, has a veto.

But the Trump administration has denounced Iran’s involvement in Yemen and Syria, condemned its tests of advanced missiles and seems determined to confront the Shiite clergy who control the country.

So if Assad stays in power, peace seems unlikely. Instead, the country may be partitioned, a nightmare scenario that would lead to yet more population displacements and a central government completely dependent on Iran.

In France, meanwhile, Macron has made it clear his government will no longer continue his predecessor’s demands that removal of Assad be a precondition for any peace settlement. “The real change I’ve made on this question, is that I haven’t said the deposing of Bashar al-Assad is a prerequisite for everything. Because no one has introduced me to his legitimate successor,” he told European newspaper reporters last month.

Here, too, it’s hard to see how Macron’s new position can prevail.

Turkey, a U.S. NATO ally just like France, is adamant that Assad has to go. Turkish President Recep Tayyip Erdoğan said Wednesday that Macron has “a wrong approach in recognizing Assad.” It is “wrong to approve the continuation in power of a terrorist who caused the deaths of 1 million people,” he said, giving a death toll far in excess of most estimates. “The ones who want Assad to stay in power are the ones pursuing their own interests,” he said.

Turkey has a 600-mile border with Syria. Its own forces now control 810 square miles inside the country and they are poised to expand that pocket. So it, too, has a veto. Should Assad stay, it’s unlikely Turkey will withdraw its forces, effectively partitioning Syria.

One thing France could do is to withdraw covert aid provided by the “Friends of the People of Syria” grouping to rebel forces protecting some 3 million civilians in Idlib and other northern provinces. But that would lead to yet another humanitarian catastrophe, as much of the population would flee to Turkey, which already is hosting 3 million refugees. And Turkey might then reopen the spigot and allow them to flee to Europe, France included.

It’s an unthinkable scenario for Europe, and the U.S. and Turkey would no doubt veto it in any case.

France is the former colonial power in Syria and has given refuge to many Syrian civilian and military defectors, but Macron, the newest, youngest and perhaps most charismatic politician on the world scene today has yet to figure it out.

Standing next to Putin during his visit to Versaille in May, Macron said France will intervene unilaterally if Assad deploys chemical weapons again. That’s clear enough, and echoes unabashedly the position of the Trump administration.

But Macron also declared another “red line,” reiterated in his June 21 interview: protection of “humanitarian corridors” in Syria, and he has yet to explain what exactly that means.

“It is unclear what is really new,” said Jan Egeland, the UN humanitarian envoy for Syria. The concept of humanitarian corridors is “specific, complicated and not very realistic” for reaching the 10 or more areas that are still under siege or are hard to reach, he said in an email. Humanitarian aid flows only with the permission of the Syrian government and when all armed actors on the ground agree to suspend hostilities, both of which “are too seldom happening,” said Egeland.

If Macron was referring to the current impasse in aid delivery as a red line, he’d easily find cause for an immediate intervention.

Western powers are not the only ones bogged down in Syria, their goals subject to others’ veto.

The principal Kurdish force in northern Syria, the People’s Protection Units or YPG, which for the past two years has served the U.S. as a ground proxy to fight ISIS, wants to create a band of territory linking mostly Kurdish pockets in northern Syria into one entity. But Turkey has intervened to stop that from happening.

Turkey would like to oust the YPG from northern Syria altogether on the grounds that it is the Syrian affiliate of the Kurdistan Workers’ Party or PKK, which is at war with Turkey. But the U.S. has sent its own forces to Syria’s border with Turkey to prevent that from happening.

Even Iran may have underestimated the challenge of making permanent gains in Syria as a reward for supporting Assad. Just a few weeks ago, Iranian news media reported that the country’s main aim in the Syrian war is to establish a land corridor to the Mediterranean that will enable it to supply the Hezbollah militia in Lebanon. Meanwhile, Iran actively supported the YPG’s attempts to establish a band of territory to further just such a goal.

But the lineup of powers opposing Iran is formidable—including Turkey, the United States, and Israel—and it will be hard, if not impossible, to achieve.

The bottom line, once again, is a stalemate that no new U.S.-Russian initiative is likely to resolve.

—with additional reporting by Duygu Guvenc in Ankara