Chemical Weapons Allegations in Sudan: New Documents Open a Legal and Political Front in the War

Sudan’s war is entering a new and more complicated phase following the emergence of classified documents reportedly containing information about a program to develop and produce chlorine-based munitions and their alleged use in combat against the Rapid Support Forces (RSF). If the documents and the information they contain are ultimately authenticated, the issue could go beyond a potential violation of the laws of war and open a new path toward international accountability, exposing the conduct of the Sudanese Armed Forces and its leadership to greater legal and political scrutiny.

Yet the significance of the information now circulating does not mean it should be treated as conclusive evidence. Leaked documents, regardless of their volume, must be authenticated, placed in context, and examined for the integrity of their chain of custody. Establishing the use of a chemical weapon also requires determining what substance was used, where it came from, how it was deployed, and which individuals or institutions ordered or carried out its use.

The issue therefore currently stands at a critical point between the existence of indicators warranting investigation and the establishment of criminal responsibility.

New Documents Bring the Chemical Weapons Issue Back to the Fore

According to a Sudanese report published in September 2026, approximately 150 documents, photographs, videos and audio recordings, along with thousands of text messages, form part of a dossier that the newspaper said was provided by a Middle Eastern intelligence agency to The New York Times.

Reports attribute some of the material to the phones of senior Sudanese military officers and say that it contains details of a program to develop chlorine-based munitions during 2024, as well as bomb designs and information about tests allegedly conducted in desert areas.

The allegations are significant because they do not merely concern the possible use of a chemical substance on the battlefield. They reportedly point to an organized process of development, production and testing. If an independent investigation were to verify these elements, the implications would be considerably more serious than those of an isolated use, as they could indicate the existence of an institutional structure connected to a prohibited weapons program.

The nature and origin of the material, however, require considerable caution. Moving from digital documents or messages attributed to officials to proof of a chemical weapons program requires rigorous technical and legal procedures, including digital forensic examination, authentication of documents and devices, and comparison of the information with physical evidence from the battlefield.

What Was Known Before the New Documents?

This is not the first time allegations of chemical weapons use have emerged in connection with the Sudanese war.

In 2025, the United States began imposing punitive measures on Sudan after accusing the Sudanese Armed Forces of using chemical weapons during the war. The issue also remained under consideration within the Organisation for the Prohibition of Chemical Weapons (OPCW), which received requests from member states for clarification from the Sudanese government regarding the allegations.

In July 2025, the OPCW Technical Secretariat said it was following allegations concerning Sudan but had not, at that time, received sufficiently documented information to warrant further action. The organization also transmitted formal requests for clarification to Sudan.

In March 2026, the United States told the OPCW Executive Council that it had concluded that chemical weapons had been used in Sudan in 2024. Washington called on Khartoum to declare any chemical weapons production facilities or chemical munitions and to cooperate with the organization in verifying and addressing the issue.

These developments point to an important distinction: the controversy did not begin with the newly reported documents. Rather, the leaks have emerged within an international case that was already under scrutiny.

Between Allegation and Proof

One of the central challenges in this case is the need to distinguish between three different levels of evidence.

The first is the existence of indications or testimony concerning symptoms associated with exposure to a toxic substance. Such evidence may raise suspicion, but it is not by itself sufficient to identify the substance or establish who was responsible.

The second is establishing the presence of a prohibited chemical substance at a particular location. This requires environmental or medical samples and independent laboratory analysis.

The third—and most complicated—is attributing responsibility to a specific institution or individual. That requires evidence concerning the chain of command, orders, access to the weapon and the circumstances and method of its use.

The OPCW’s investigative methodology illustrates the importance of this sequence. Where conditions permit, its investigations can involve interviews with victims, witnesses, first responders and medical personnel; the collection of environmental and biomedical samples; examination of weapon remnants and documents; and the submission of samples to accredited independent laboratories for analysis.

The newly reported documents may therefore be highly valuable to an investigation, but they do not by themselves complete the evidentiary process.

Why Does Chlorine Present a Particular Legal Question?

Chlorine has extensive industrial and civilian applications. The mere discovery or possession of chlorine, or materials containing it, does not establish the existence of a chemical weapons program.

Using a toxic chemical as a weapon of war, however, is fundamentally different from its legitimate civilian or industrial use. The Chemical Weapons Convention prohibits the use of toxic chemicals as weapons, regardless of whether the substance itself has legitimate applications under normal circumstances.

This makes the purpose, method and circumstances of use critically important.

If an independent investigation establishes that a chemical substance was deliberately used to harm opposing forces or civilians through its toxic properties, the issue would move from the legitimate use of an industrial chemical into the domain of prohibited chemical weapons.

Sudanese Military Denies the Allegations

The Sudanese Armed Forces rejected the allegations contained in the reports, describing them as lacking a material basis and stressing that Sudan is a state party to the Chemical Weapons Convention.

The position carries legal and political significance because, in any potential international investigation, the Sudanese government would be expected to provide information enabling competent authorities to determine whether a prohibited program or use existed.

The denial does not eliminate the need for an investigation. At the same time, establishing responsibility cannot be based solely on the opposing narrative.

This makes transparency and cooperation with international investigative mechanisms critical factors in determining the strength or weakness of the allegations.

Military Leadership Faces a Different Question

According to the reports, some of the material contains messages allegedly connected to the Sudanese military leadership and purportedly indicating direct knowledge of the alleged project.

If the authenticity and context of those messages were established, they could raise questions extending beyond whether chemical weapons were used to the issue of command responsibility.

However, this form of responsibility cannot be established merely because the name of a military commander appears in a message or because a commander is referenced in a conversation. It requires more complex evidence concerning the nature of any order, the extent of knowledge, effective control, and the relationship between the leadership and those who allegedly carried out the act.

A serious investigation would therefore need to distinguish between alleged knowledge, approval, ordering, direct participation and command responsibility.

A New Accountability Issue in a War Already Marked by Impunity Concerns

Sudan’s war, which began in April 2023 between the Sudanese Armed Forces and the Rapid Support Forces, has been accompanied by widespread allegations of serious violations of international humanitarian law by the parties to the conflict.

The war has produced a large-scale humanitarian crisis, with high numbers of casualties and millions of displaced people, while food insecurity and famine have worsened in several areas.

Against this backdrop, the introduction of chemical weapons allegations into the war could significantly raise the political and legal stakes.

The issue concerns not only potential victims but also Sudan’s future relations with international organizations, the possibility of additional sanctions, and the potential referral of evidence to relevant international or national judicial mechanisms.

Why Does the Case Require an International Investigation?

Human rights organizations have called for independent access to locations believed to have been involved in the development, testing or use of such weapons, as well as examination of remnants of munitions, containers, aircraft and delivery systems and independent interviews with witnesses and victims.

Such demands are consistent with the nature of chemical weapons investigations, which require a high degree of scientific expertise and independence.

The OPCW provides a clear model for this type of investigation. In previous investigations, the organization has emphasized that establishing the presence of a chemical substance depends on the independent collection and analysis of physical evidence, rather than on testimony or photographs alone.

The strongest test of the new allegations will therefore not be competing political statements, but evidence that can be independently examined and verified.

Potential Political Consequences

If the allegations are substantiated, Khartoum could face additional international pressure beyond existing sanctions. Pressure could increase for full cooperation with the OPCW, and measures targeting officials or institutions linked to the alleged program could potentially be expanded.

If the evidence fails to substantiate the allegations, that outcome would also be significant, as it would limit the ability of international actors to use the case as a basis for expanding sanctions or political pressure on the Sudanese government.

In either case, the issue extends beyond the legal sphere. Sudan’s war has already become the arena for complex regional and international competition, and credible evidence of chemical weapons use could alter the priorities of external powers involved in the conflict.

What Could This Mean for the Course of the War?

The disclosure of the documents, by itself, may not alter the balance of power on the ground. It could, however, change the political and legal character of the war.

In armed conflicts, the type of weapon used can influence the level of international engagement, the nature of sanctions, the priorities of investigations and potentially even the conditions surrounding a future political settlement.

The new allegations could also affect the international standing of the Sudanese Armed Forces at a time when it is seeking to consolidate its position as the country’s official state institution in opposition to the Rapid Support Forces.

The other side of the issue is that any investigation must not become a mechanism for overlooking other violations committed by the parties to the conflict. Effective accountability should not be selective; it should address serious violations regardless of the identity of those responsible.

Three Possible Paths

Three broad trajectories can be envisaged for the case.

First: An international investigation establishes the evidence.
If competent authorities gain access to sites, samples or original documents, the case could move from journalistic allegations toward a stronger evidentiary basis, potentially leading to additional international measures.

Second: A limited investigation because access remains difficult.
Evidence may remain incomplete because of the continuing war and the difficulty of reaching relevant sites, leaving the issue unresolved and confined largely to competing allegations.

Third: A negotiated path toward technical cooperation.
Sudanese authorities could agree to strengthen cooperation with the OPCW and facilitate technical verification efforts, allowing the issue to be addressed without immediately turning it into a broader international political confrontation.

Conclusion

The significance of the newly reported documents lies in their ability to return the issue of chemical weapons to the center of the debate over Sudan’s war. They should not, however, be treated as a final judgment on responsibility.

Fundamental questions remain unanswered: Were chlorine or another prohibited chemical substance used as a weapon? Where did this occur? Who used it? Was an organized entity behind the operation? And who, if anyone, authorized it?

These questions will not be resolved through political statements or competing accusations. They require independent technical investigation, secure evidence chains, laboratory analysis, and access to incident sites and witnesses.

The most important development may therefore not be the contents of the leaked documents themselves, but whether they can be transformed into verifiable evidence before independent international bodies.

If the allegations are substantiated, Sudan’s war will have entered an even more serious phase in terms of international accountability. If they are not, the case will once again demonstrate why intelligence assessments and journalistic leaks should not be converted into predetermined judgments before the evidentiary process is complete.

In either case, the central challenge is to ensure that the truth is not lost amid the political and media warfare surrounding Sudan’s conflict.