White Phosphorus in Lebanon: What the Controversial Weapon Does and Why Its Use Is Under Scrutiny

Israel's military has employed white phosphorus in southern Lebanon, according to reporting by Al Jazeera, raising fresh questions about the use of a weapon whose effects on civilians and the environment are among the most severe of any conventional munition. The substance is not a conventional explosive in the usual sense. It is an incendiary agent that burns at extraordinarily high temperatures and can continue burning long after it makes contact with a target.

White phosphorus is a chemical that ignites spontaneously when exposed to oxygen. Once a shell or bomb carrying the substance bursts, the material scatters and immediately begins to burn. The resulting fires are extremely difficult to extinguish and can reignite even after they appear to have been put out, which makes treating wounds caused by the substance especially challenging for medical personnel.

The human toll of exposure is severe. White phosphorus can inflict deep burns that penetrate skin and muscle tissue, and because particles of the substance can remain embedded in wounds, burns may flare up again during treatment or recovery. Inhaling the toxic smoke produced by burning white phosphorus can damage the lungs and respiratory tract, while prolonged exposure to the fumes may cause additional systemic harm.

Beyond its immediate effects on people, white phosphorus has a lasting impact on the landscape. The intense heat and persistent fires can scorch farmland, destroy crops and vegetation, and leave soil contaminated. In southern Lebanon, where agriculture is a central part of local livelihoods, the use of such a weapon in populated or cultivated areas threatens both food production and the economic stability of communities already affected by conflict.

International law restricts how white phosphorus may be used. While the substance is not banned outright as a weapon, its employment in densely populated areas is constrained by legal obligations requiring parties to distinguish between military targets and civilians and to take precautions to protect non-combatants. Using an incendiary agent in a manner that indiscriminately harms civilians can amount to a violation of these rules.

The concerns are compounded by the nature of white phosphorus itself. Because the substance spreads over a wide area when dispersed and cannot be aimed with the precision of many modern munitions, its use near residential neighborhoods carries a high risk of civilian casualties. The toxic smoke it generates can also drift beyond the immediate impact zone, affecting people who were never intended to be targeted.

Israel has used white phosphorus in southern Lebanon, according to the reporting. The precise circumstances, locations and targets of these incidents are matters that international observers and human rights organizations have repeatedly called for scrutiny and accountability. Questions typically center on whether the weapon was deployed in a manner consistent with the legal requirement to protect civilians.

Medical and humanitarian groups have long warned about the difficulties of responding to white phosphorus injuries in conflict zones. Treatment requires specialized care, including the removal of embedded particles and management of burns that may worsen over time. In areas where hospitals and clinics are already under strain, such injuries place an additional and often overwhelming burden on health workers.

The environmental consequences also linger. Fires caused by white phosphorus can spread rapidly through dry vegetation, and the residue left behind may contaminate water sources and soil. For farming communities in southern Lebanon, the destruction of fields and orchards can mean the loss of income for an entire season or longer, deepening the hardship caused by displacement and insecurity.

The use of white phosphorus has drawn criticism in past conflicts as well, and the debate around it reflects broader tensions in the laws of war. The central issue is not only whether a particular weapon is lawful in the abstract, but how and where it is used. Strikes near homes, markets and farmland intensify the risk that civilians will bear the consequences.

For residents of southern Lebanon, the presence of such weapons adds another layer of fear to daily life. Families who have already fled violence or seen their neighborhoods damaged must also contend with the possibility of burns, respiratory harm and the destruction of the land they depend on. The psychological weight of these threats can be as significant as the physical injuries themselves.

International scrutiny of the use of white phosphorus is likely to continue as long as reports of its deployment emerge. Human rights monitors and legal experts argue that accountability requires transparent investigations and clear explanations of how and why such a weapon was chosen. Without that, the consequences for civilians and for the credibility of the laws governing conflict remain unresolved.

The broader lesson is that weapons with wide-area and persistent effects demand a particularly high standard of care. In populated areas, the margin for error is small, and the harm caused by a single incident can last for years. As southern Lebanon contends with the aftermath, the question of whether the use of white phosphorus met legal and humanitarian standards is one that will not easily fade.