Desperate to help Syrians stuck on Jordan's sealed border, U.N. agencies agreed late last year to an aid system that critics say handed much of the control over aid distribution to Jordan's military and a Jordanian contractor, and also involved armed men on the Syrian side.
Since then, the system has broken down repeatedly and only sporadic aid shipments have reached two remote desert camps on the border that house thousands of Syrians displaced by war. Rival groups in the larger Rukban camp accuse each other of diverting aid, and black marketers flourish.
Separately, the Tribal Army, a Syrian militia that says it was asked by Jordan to police Rukban, struck deals on access and protection with World Vision and Cap Anamur, but the two foreign aid groups pulled out of Rukban after bombs targeted Tribal Army forces near their installations.
Critics say the struggle to provide aid to stranded Syrians reflects the international community's wider failure in responding to the refugee crisis. Some 5 million Syrians have fled their homeland since 2011, but countless others are trapped in a country at war after neighboring Jordan, Lebanon and Turkey — which absorbed most of the influx — largely closed their borders.
"Syria is locked in, and I think this is an issue which is not at all in the public debate or being raised by the aid agencies," said Kilian Kleinschmidt, a former Jordan-based U.N. refugee agency official.
Jordan closed its border for good in June 2016 after an Islamic State car bomb attack launched from near Rukban killed seven Jordanian border guards.
Since then, international aid organizations have wrestled with the dilemma posed by sending aid to an off-limits area.
Do they join a system that relies on armed escorts and can't guarantee aid reaches the intended recipients? Or do they uphold humanitarian principles if at the cost of not helping women and children trapped in harsh conditions?
The U.N. refugee agency, which leads aid efforts on the border, and several European nations defended the decision to engage.
U.N. agencies "are doing an extraordinarily good job in extraordinarily difficult circumstances to try to get as much aid as possible to those people, with as much assurance as they can," said Edward Oakden, the British ambassador to Jordan. Walking away is a cop-out, he said.
The European Union took a different view.
Its humanitarian arm, ECHO, decided in November, as the new system took shape, that it would not fund distributions in the no man's land known as the "berm," named after parallel lines of earthen ramparts loosely marking the border.
"There is no guarantee that humanitarian assistance, as limited as it may be, actually reaches the intended beneficiaries," the European Commission's spokesperson's office said in a statement. "We are not aware of a system in place to ensure that aid provided cannot be diverted."
The commission said it "believes that the use of military assets, armed escorts, joint humanitarian-military operations and any other actions involving visible interaction with the armed groups are taking place in the distribution" when they should be a last resort.
It called for negotiations with Jordan's army to get a better deal, but the international community doesn't have much leverage.
The West needs the goodwill of host countries because it wants to discourage Syrians from migrating onward, including to Europe.
Jordan counters criticism of its policies, such as the border closure, by noting that it has absorbed far more refugees than wealthier Western countries, which have also failed to fully meet aid pledges to the region. The kingdom also argues that Islamic militants mingling with Syrians on the border pose a security threat.
Government spokesman Mohammed Momani said Jordan is doing everything it can to help aid agencies help the Syrians and get aid to the camps.
Even before the border closure, Jordan increasingly restricted entry to Syrians. Since 2014, they've been massing on the eastern edge of the shared border. The Rukban and Hadalat camps sprang up, with what the U.N. estimates are now 45,000 to 50,000 residents. Camp activists say the population is twice as large.
For a few months before the border closure, Syrians could climb over the berm to pick up supplies or get medical treatment from aid groups on the Jordanian side. After the closure, different methods were tried, including aid drops by crane.
In the fall, the U.N. refugee agency and Jordan's military agreed to set up a distribution center between the berms, 7 kilometers (4.5 miles) from Rukban.
A Jordanian contractor began operating from behind a security barrier, with Syrians from Rukban, often heads of households, passing through barrier passages one by one to pick up parcels of food and other aid. Iris scans confirm their identity.
The Tribal Army said it is in charge of crowd control on the "Rukban side" of the barrier, as hundreds of people gather on distribution days.
The system broke down repeatedly, with what were to be monthly distributions frequently disrupted by security threats, unruly crowds or severe weather.
The first round of distributions stretched from November to January. The second round only began in May and is ongoing, with some 35,500 people so far having received food and other items, the U.N. refugee agency said.
Another challenge is keeping track of where the aid ends up.
U.N. agencies can monitor movements at the distribution center through cameras, but don't know what happens in Rukban, where rival rebel groups wrestle for control.
The U.N. refugee agency believes the aid reaches needy families, based on what it hears from Rukban patients visiting a U.N. health center in Jordan, several kilometers (miles) from the camp.
The U.N. said it vaccinated 15,000 children against polio, and will soon begin measles and tetanus vaccinations. The EU said it is funding those efforts.
The dominant group in Rukban appears to be the Tribal Army, with followers from rural parts of southern Syria and tribal ties to Jordan.
The group is being trained, supplied and funded by Jordan, spokesman Mohammed Adnan said at the group's office in the Jordanian city of Mafraq, near Syria.
The Jordanian military did not respond to a request for comment about such payments. Jordan's army chief has confirmed that Jordan is training the Tribal Army to fight "terrorists near the border."
Adnan alleged that other groups in Rukban are trying to instigate trouble, such as the Tribal Council of Palmyra and Badia, which bills itself as a grass-roots service organization. Adnan said some civilians in the camp are also armed, along with the Eastern Lions, a rebel faction.
Palmyra Council spokesman Omar al-Binai alleged that only about half the aid reaches the intended recipients, and that those with links to the Tribal Army ``benefit the most'' from the current arrangement.
Adnan rejected the allegations, saying he believes most of the supplies reach the right people. He accused the Palmyra Council of trying to discredit his group in hopes of expanding control in the camp.
Several dozen private traders have benefited from aid shortages, selling food and supplies from elsewhere in Syria, often on credit, al-Binai said. Foreign aid is often sold, below value, to pay back the merchants, he added.
A labor market has sprung up, and some residents get money from abroad via WhatsApp transfers, he said.
U.N.-provided water has also become a commodity after sabotage damaged a water access point in the camp last month. Camp residents now rely on water from a site several kilometers away and have to pay for its transport.
In the current system, aid is only provided to the berm by U.N. agencies.
Two private international groups, World Vision and Cap Anamur, said they negotiated separate access deals with the Tribal Army after Jordan's border closure.
Cap Anamur, a Germany-based medical aid group, said it set up a field hospital in Rukban, consisting of six pre-fab trailers shipped over the border by the Tribal Army. World Vision sent diapers, toothpaste and other supplies that it stored in a tent in Rukban ahead of distribution.
Tribal Army posts near the clinic and the tent were targeted in separate bombings last fall that killed several guards and prompted the groups to pull out.
Chris Weeks, a spokesman for World Vision, said the group was aware of the challenges from the start.
"We recognized that it was an incredibly tough environment and that there were no perfect answers when it came to helping people who were suffering," he said.