DIMITAR DILKOFF / AFP / Getty Images A Syrian rebel patrols an area in the Sheikh Maqsud district of the northern Syrian city of Aleppo on April 11, 2013.

It takes a major crisis for the U.N.’s humanitarian agencies, often rivals, to speak with one voice. But the calamitous death and destruction in Syria prodded five chiefs of U.N. organizations to issue a desperate joint plea on Tuesday, on YouTube and in newspapers across the world, warning that unless governments find a political solution to end the two-year war, they could be forced to end some relief programs for ravaged Syrian communities. “After all this, there still seems an insufficient sense of urgency among the governments and parties,” says the message, which was rushed into production over the past 10 days, as estimates of those killed in the conflict were put above 70,000. “We are precariously close, perhaps within weeks, to suspending some humanitarian support.”

As a measure of how dire the suffering in Syria’s war zones has become, the U.N. organizations’ joint appeal was rare, and included filmed messages from the chiefs of the U.N. Children’s Fund (UNICEF) in New York City; the U.N. High Commissioner for Refugees, the World Health Organization and the U.N. Office for the Coordination of Humanitarian Affairs, all in Geneva; and the World Food Programme in Rome. In a departure from their more characteristically neutral tone, the executives let their anger show on the video, delivering a blunt message to politicians: that their paralysis over how to end the war is pushing the entire region to “a tipping point.”

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“We ask that [politicians] use their collective influence to insist on a political solution to this horrendous crisis before hundreds of thousands more people lose their homes and lives and futures,” they say. “The needs are growing while our capacity to do more is diminishing, due to security and other practical limitations within Syria as well as funding constraints.”

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U.N. officials have issued countless reports about conditions inside Syria since the conflict erupted in February 2011. But as the war grinds into its third year, the relief organizations are already strained by having to tackle the current, truly critical emergencies, and reeling at the daunting prospect of how Syria might one day be pieced together as a country again, once the war finally ends.

The mass disruption, say officials, has caused such deep shifts on almost every social level, that families could take years, maybe generations, to recover. Aside from the spectacular loss of life, U.N. agencies estimate that thousands of schools have been destroyed, and UNICEF estimates that only 6% or so of children from Aleppo — Syria’s economic powerhouse before the war — currently attend classes, down from 85% just two years ago. Vaccination programs are also patchy. Although UNICEF has mobile teams, which operate only under the aegis of Bashar Assad’s Health Ministry but which cross into rebel-held areas to immunize children, the organization is often forced to throw out vaccines when it cannot be certain of how they’ve been handled along the way. “The bottom line is that the dithering by the international community must end because if it continues, it will have a catastrophic impact on the region for a long time to come,” says UNICEF spokeswoman Sarah Crowe, speaking from New York City. “We’re looking for something much more important than funds. A political solution must be found to the human suffering.”

That kind of negotiated end to the war has until now been almost impossible to find. After weeks of considering whether to arm some Syrian rebel groups, France and Britain appear to have abandoned the idea, after the rebels’ al-Nusra Front pledged allegiance to al-Qaeda last week. At the U.N. Security Council, Russia and China have used their veto powers to block all attempts to impose a U.N. arms embargo against Assad or to tighten global sanctions against his regime. And although U.N. Secretary-General Ban Ki-moon announced last month that he was sending a team to investigate whether Syria’s regime had used chemical weapons against the rebels, weeks later, the team has yet to be given visas to the country.

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Then there is Assad himself. With Russia and Iran still in strong support, the Syrian leader has felt little urgency to try to negotiate a settlement with the rebels. Syria’s Deputy Foreign Minister Faisal al-Miqdad on Monday ruled out any idea that Assad could leave office, telling the Guardian in Damascus, “There will be no Syria if President Assad steps down … If he leaves now before we agree on a political plan among all Syrians, Syria will no longer be on the map.”

With no fresh ideas about how to end the war from Western leaders or Russian President Vladimir Putin, the U.N.–Arab League envoy to Syria, Lakhdar Brahimi, has shuttled between Western and Arab capitals for eight months, attempting to inch the warring parties closer to negotiations or even a temporary cease-fire. Brahimi is due to brief the U.N. Security Council in New York City on Thursday about his work. Brahimi, a former Algerian Foreign Minister, has made it clear that Assad cannot be part of any transitional government — and in recent days, Arab and Russian media have speculated that Brahimi could quit in frustration. No wonder, then, that the U.N. humanitarian chiefs seemed near desperation in this week’s appeal to leaders. “Summon and use your influence, now, to save the Syrian people and save the region from disaster,” they said.

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