The rebellion west of Damascus is no more. After four years of fighting, the Syrian army retook rebel-held Darayya on August 25. Weeks of heavy combat, ceaseless bombardment, and a spiraling humanitarian crisis prompted by the government’s long-running blockade on humanitarian convoys finally brought Darayya’s defenders to their knees.

A deal was signed in which the rebels agreed to evacuate to northern Syria, along with a small number of civilians that had remained in the bombed-out city. Other civilians and fighters who had agreed to lay down their arms were bussed to government-controlled shelters in the Damascus region, but they were not allowed to remain in Darayya. As explained by the Century Foundation’s Sam Heller, both rebels and government loyalists see the city’s fall as highly symbolic:

The loss of Darayya is a watershed in Syria’s war. For many in Syria’s opposition, Darayya represented the best of the Syrian revolution—a bastion of civil activism and nationalist, “Free Syrian Army” rebels that held together and persevered for years against overwhelming odds, even as rebel-held areas elsewhere slid sideways into jihadism and factional infighting. For the regime of Bashar al-Assad and its loyalist base, Darayya was an intractable menace to the capital Damascus, sowing insecurity and violence only miles from the heart of the city and the Presidential Palace.

The international community, too, is beginning to react to what has just taken place. For the United Nations and the many humanitarian aid groups operating in Syria, Darayya’s fall has brought questions about the integrity and independence of their operations to the fore, as the conflict slowly shifts toward a new stage where more cities are likely to suffer a similar fate.

Assad Cements His Hold on “Useful Syria”

With Darayya gone, what remained of the insurgency west of Damascus unraveled. As the last inhabitants of Darayya began their voyage north, they were soon followed by people from the nearby suburb of Moadamiyeh. Despite already having signed a truce with the army, the opposition fighters in Moadamiyeh reportedly came under pressure to leave the region after Darayya’s surrender. “It wasn’t a negotiation or a conversation, it was a threat,” a Moadamiyeh-based media activist told the Al-Jazeera website. “They basically told us: ‘Either surrender or we burn Moadamiyeh.’”

East of Damascus, the insurgents are fighting on, but government forces are making significant progress there, too. Rebel defenses in the so-called Eastern Ghouta region collapsed last spring after a bout of vicious infighting. The southern and eastern flanks of the enclave have now crumbled, and Assad’s forces are slowly moving toward the outskirts of the region’s main city, Douma. Meanwhile, the government has reimposed its siege of East Aleppo in the north.

What this means is that the government seems to be slowly consolidating its hold on the most densely populated regions of Syria—what some have called “useful Syria.” But it is also true that the army is weakening elsewhere. In the Euphrates region, for instance, it has lost most of the areas it controlled to the self-declared Islamic State. A few strongholds remain as pockets in a sea of Kurdish-controlled territory. There, the balance of power is not in Assad’s favor, with the Kurds recently cracking down hard on pro-Assad militias in Hasakah. Elsewhere, in rural rebel-held regions such as Idlib, government institutions have been brutally uprooted. But along Syria’s central-western axis, stretching from Aleppo past Hama and Homs to Damascus, the rebels are now slowly being hemmed into pockets of mostly rural territory, as the government secures the great cities and wipes out lingering resistance. Assad may not be in a position to retake all of Syria militarily, but with Iranian and Russian support he seems to be winning in the areas that matter most to him.

Of course, nothing should be taken for granted. The Aleppo situation remains precarious and the army recently suffered severe defeats on an undermanned front in North Hama. No one outside the presidential palace—and perhaps no one inside it, either—seems certain how sustainable is the government’s position in the longer term, considering the frail Syrian economy, the shortage of loyal fighters, and the structural problems eating at the state from the inside. But though Assad may be weakening in the long run, the opposition is poorly placed to exploit this. The factions of the insurgency that are most acceptable to the West have increasingly been diverted away from active fronts in support of separate proxy projects to protect neighboring borders, while the mainstay of the insurgency is becoming too infected with jihadi radicalism for Western nations to seriously contemplate supporting it.

Sieges, Starvation Tactics, and Expulsions

The fall of Darayya, therefore, poses thorny questions for the international community and humanitarian organizations. Starvation tactics have been practiced by the Assad government (and some of its opponents) for years, although such actions are unambiguously war crimes. In February 2014, the United Nations Security Council unanimously adopted a resolution on Syria stressing “that starvation of civilians as a method of combat is prohibited by international humanitarian law.” But the warring parties simply brushed it off.

As demonstrated in places such as Yarmouk, Madaya, and now Darayya, sieges and the collective punishment of civilians are among the most effective tactics of the Syrian war. They allow the attacking forces to contain an area with a minimal likelihood of incurring casualties, while extracting financial and political concessions for what would normally be seen as basic human decency: giving trapped civilians food to eat. If the perpetually undermanned Syrian army is to expand further without becoming dangerously overstretched, it is likely that it will increasingly rely on Darayya-style solutions—including by ordering the expulsion of civilians from areas that would be costly to control and police.

For the opposition, this amounts to a strategy of political and sectarian cleansing. While Darayya was a complex affair—many of its inhabitants were allowed to stay in government-held territory, though not in their hometown—it is easy to see how expulsions officially motivated by military factors could be influenced by the war’s ever-present sectarian dynamics. In some areas, the distinction will likely be academic.

Though it has not yet been implemented, a similar deal has already been agreed with the starved-out and jihadi-controlled Yarmouk area in southern Damascus. The Waer suburb of Homs is also negotiating a separate agreement with the government, which, less controversially, would reportedly lead to the expulsion of fighters while leaving the civilian population in place. Should the army continue to advance, such tactics could also be applied to rebel-held towns around Rastan, north of Homs, and in the Eastern Ghouta. In addition, Assad and his Russian allies are already promoting the idea of civilian evacuations from besieged Eastern Aleppo, though without much hope of gaining UN blessing.

Pragmatic Compromise or Moral Complicity?

The international aid community and the United Nations consider it to be of paramount importance to guarantee their independence and make sure that their staff do not unwittingly become handmaidens of a strategy of forcible expulsions of civilians. It would go against the grain of UN conflict-resolution principles and set a dangerous precedent by showing armed actors that they can target and deport civilians with impunity in Syria, and perhaps elsewhere.

“Should we be ignoring the fact that there is clearly a strategy at the moment to move from Darayya to Waer to Moadamiyeh in a similar pattern?” asked UN Special Envoy for Syria Staffan de Mistura. The UN’s highest humanitarian aid official, Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Stephen O’Brien, was even more blunt:

[A]greements resulting in a mass evacuation of civilians after a prolonged period of besiegement do not comply with international humanitarian law and human rights law. Let us be clear, all sieges, a medieval tactic, must be lifted. This should not be through any type of agreement which results in the forced displacement of the civilian population. What happened in Darayya should not be precedent-setting for other besieged areas in Syria. It is imperative that all those displaced are allowed to return voluntarily, in safety and in dignity, to their homes as soon as the situation allows it.

But while such returns may be imperative, that does not make them any more likely to happen. The displacement of civilians from Darayya and other cities will very probably end up being permanent. UN officials know this. It is precisely why they protest so much.