The Invisible Weapon: Why Sudan’s Chemical Weapons Allegations Demand an Independent Investigation
A new documentary brings allegations against the Sudanese Armed Forces to Washington — and Senator Chris Van Hollen says the evidence now warrants an independent OPCW investigation.
By Hayvi Bouzo
Some allegations are too serious to remain suspended indefinitely between accusation and denial. The possible use of chemical weapons in Sudan is one of them.
That was the central question raised at the September 24 Washington screening of The Invisible Weapon, an investigative documentary examining allegations that chemical weapons were used during Sudan’s brutal civil war. Produced and directed by Moroccan journalist and filmmaker Youssef Jajili, the 26-minute film does not present itself as the final judgment on what happened. Instead, it assembles testimony from affected civilians, medical information, expert analysis, open-source research and evidence concerning chemical supply chains — the kind of material that makes the case for a deeper, independent investigation increasingly difficult to dismiss. The National Press Club’s description of the film emphasizes precisely this combination of firsthand testimony, expert analysis, open-source research and documented supply-chain information.
What makes The Invisible Weapon effective is that it understands the difference between raising a serious allegation and proving one. A survivor’s account is not the same thing as a laboratory finding. A suspicious shipment does not by itself establish that a chemical weapon was deployed. Medical observations need expert interpretation, and open-source evidence needs to be verified and placed in context. But when these different strands begin pointing toward the same disturbing possibility, they create a question that cannot responsibly be left unanswered.
That question has become more urgent because the allegations are no longer confined to journalists or parties to Sudan’s conflict. In April 2025, the United States formally determined that the Government of Sudan had used chemical weapons in 2024 in violation of international law, triggering sanctions under the Chemical and Biological Weapons Control and Warfare Elimination Act. The formal U.S. determination stated that the Sudanese government had used chemical or biological weapons in violation of international law or lethal chemical or biological weapons against its own nationals.
Washington has continued to press the issue internationally. At the Organisation for the Prohibition of Chemical Weapons earlier this year, the United States said that chemical weapons had been used in Sudan in 2024 and urged Sudanese authorities to declare any relevant production facilities or chemical munitions and work with the OPCW on verification and destruction. The U.S. statement to the OPCW also warned that the risk of further chemical-weapons use remained a concern.
Sudan has rejected the allegations and has maintained that its own inquiries have not established that chemical weapons were used. That disagreement makes independent verification more important, not less. The OPCW itself has continued to consider the Sudan file, with requests for clarification and statements from Sudan, the United States and other member states appearing before its Executive Council.
It is in that context that the most consequential intervention in The Invisible Weapon comes from U.S. Senator Chris Van Hollen.
“We must ensure that these reports are independently investigated to establish the full facts,” Van Hollen says in his recorded contribution to the film.
Van Hollen states that the United States concluded that the Sudanese Armed Forces used chemical weapons and says that additional evidence has since emerged that warrants further scrutiny. He calls for an independent investigation and for accountability for anyone found responsible for abuses against civilians. Most significantly, he argues that the United States and the international community should support an investigation conducted through the Organisation for the Prohibition of Chemical Weapons. Contemporary reporting on the screening records Van Hollen making that case explicitly.
His remarks capture the gap that Jajili’s film exposes.
Governments can make intelligence assessments. Journalists can uncover documents. Researchers can track supply networks. Filmmakers can find witnesses, reconstruct events and place testimony before the public. But none of them can replace an independent international process with the technical capacity to inspect relevant sites, examine samples, interview witnesses under controlled conditions and determine what the available evidence actually establishes.
Chemical-weapons investigations are difficult under the best circumstances. In the middle of a civil war, the challenges multiply. Sites may be inaccessible or contaminated. Evidence may degrade or disappear. Witnesses may have fled the country. Medical records may be incomplete, and those possessing information may face intimidation. The longer serious allegations remain unresolved, the harder reconstructing events can become.
That is one reason The Invisible Weapon matters. Jajili does not try to turn a documentary into a courtroom. He uses investigative journalism for what it can do best: finding people whose experiences might otherwise disappear, assembling disparate pieces of evidence, identifying unanswered questions and placing them before an audience with the ability to demand further scrutiny.
The film is also important because it does not present Sudan’s war as a simple confrontation between an innocent side and a guilty one. It addresses atrocities attributed to the Rapid Support Forces alongside the allegations involving the Sudanese Armed Forces. The RSF has itself been accused of mass killings, sexual violence and other atrocities against civilians, particularly in Darfur. Accountability for those crimes does not diminish the significance of allegations involving the SAF; nor should abuses by one side provide political cover for abuses by another.
The wider record of the war also matters. Foreign weapons and military assistance have helped both sides sustain a conflict that has devastated Sudan. MidEast Journal has previously documented how Turkish drones and other military support have strengthened the Sudanese Armed Forces, including transfers of Bayraktar systems and other military equipment used in a campaign that has produced extensive civilian suffering. The chemical-weapons allegations therefore sit within a broader question about the weapons entering Sudan, the networks supplying them and the responsibility of outside actors enabling an increasingly destructive war.
The Washington screening brought those different dimensions together. After the film, journalist Areej Elhag, Abdullahi Boru of Refugees International and Abby Schneiderhan of C4ADS discussed Sudan through the lenses of journalism, displacement and illicit supply networks. The panel reflected the structure of Jajili’s investigation itself: the testimony of civilians cannot be separated from the humanitarian catastrophe surrounding them, just as questions about a suspected chemical attack cannot be answered without examining how relevant materials might have been acquired, transported and used.
This is ultimately where The Invisible Weapon is strongest. It does not ask the viewer simply to accept an accusation. It asks why an allegation of this magnitude — supported by a formal U.S. determination, civilian testimony and a growing body of investigative material — has still not been conclusively resolved through an independent international process.
The OPCW exists precisely because chemical-weapons allegations require technical verification rather than political assertion alone. Sudan is part of the Chemical Weapons Convention system, and the organization’s Executive Council has continued to address questions surrounding the Sudanese case. The United States has urged Sudanese officials to work with the OPCW on verification; Van Hollen is now calling for a full independent investigation capable of establishing the facts.
For Jajili, getting the story into a Washington screening room was itself an achievement. Sudan’s war has become dangerously easy for the outside world to overlook despite enormous civilian suffering, displacement and repeated allegations of atrocities. The Invisible Weapon takes one particularly grave part of that war and puts it before journalists, diplomats and policymakers who might otherwise encounter it only as another line in a briefing.
A documentary cannot compel military officers to surrender records. It cannot guarantee access to suspected sites or preserve every piece of physical evidence. It cannot issue a legal judgment.
But it can make continued indifference harder.
The Invisible Weapon has done that. It has brought witnesses, allegations and evidence into the public conversation and given Van Hollen’s call for an independent investigation a wider platform.
The question left after the Washington screening is therefore no longer simply what the film shows. It is whether the allegations it documents will now receive the independent scrutiny necessary to determine what happened — and, if chemical weapons were used, who was responsible.
Hayvi Bouzo is a Syrian-born American broadcast journalist, Co-Founder and Co-Editor of Middle East 24 (ME24), and Co-Founder and Executive Director of Yalla Productions. She has spent nearly two decades covering U.S. and Middle East foreign policy, interviewing guests at the highest levels of American government and politics. Her writing has appeared in Newsweek, The Jerusalem Post, and Khaleej Times.