Legal issues arising out of the use of depleted uranium in Syria

The United States confirmed that Depleted Uranium (DU) ammunitions were used in Syria. The use of such weapons has long been criticized for posing health risks to both combatants and civilians. What is the potential legal issues arising out of the use of DU in non-international armed conflicts?

Legal issues arising out of the use of depleted uranium in Syria

The U.S Central Command confirmed that over 5000 rounds of Depleted Uranium ammunition (DU) were fired during an air raid against ISIS in November 2015. It directly conflicted with the promises made by US officials not to use such armaments during the military operations in Syria. This article would explore some controversies arising from the use of DU and the potential legal framework applicable to govern the use of DU in the context of the coalition airstrikes in Syria.

Why is the use of DU controversial?

The use of DU ammunition has been considered controversial because of its potentially harmful effects on the environment and human health. It was alleged that the enriched uranium exposure resulted in an increase in birth defects in Fallujah. The dust or fragments resulted from the use of DU ammunition could also contaminate the environment through air, soil, and water. However, there has not been any conclusive research or evidence which directly links the adverse effects on human and environment to the use of DU ammunition.

What does international law say about the use of DU ammunition?

The legality concerning the use of DU projectiles had been considered by the ICTY’s Committee established to review the NATO bombing campaign. Regarding the use of DU by the NATO in Kosovo, the Committee considered that there was no absolute prohibition against such use. Noticing that there existed a scientific debate regarding the impact of the DU projectiles, the Committee left the issue to the future when there may be general consensus favoring such prohibition. However, the Committee considered the rules under international humanitarian law, especially in relation to environmental harm, remain applicable to regulate the use of DU in each particular circumstance of the armed conflict.

Applicable rules of international humanitarian law

In the lack of any treaty regime which regulates the use of DU ammunition, international humanitarian law (IHL) would be the primary regime that governs the use of DU in armed conflicts.

Firstly, the use of DU could constitute an indiscriminate attack which is prohibited by IHL as the long-term effects could not be limited to military objectives. This view is supported by a resolution adopted by the UN Sub-Commission on Human Rights which listed DU as one of the weapons with indiscriminate effects. However, the rule set forth in Art.51 (4) of Additional Protocol I only applies to international armed conflicts (IACs). Additional Protocol II, the legal instrument which governs the conduct in non-international armed conflicts (NIACs), contained no such provision. Although it was argued by the ICRC in its Customary IHL Study (at Rule 11) that a similar rule should also apply to NIAC, this position has not yet been tested. The reliance on customary international law also allows states with large piles of DU to claim persistent objectors to such rule. Similar objections have already been raised by states with nuclear weapons.

Secondly, IHL bans weapons that cause superfluous injury or unnecessary suffering. The rule is also derived solely from the AP I at Art.35(2) with an untested customary basis. Also, the words “injury” and “suffering” seem to require direct causations which might exclude long-term side effects from the calculation of harm. In fact, those commonly cited prohibited weapons, such as incendiary weapons, they all aimed at creating direct harm on individuals.

In light of the lack of direct causation between the use of DU and the harm suffered, the prohibition against the weapon which causes long-term, widespread and severe damage to the natural environment is arguably the best fit for the scenario. Given that Uranium 238 has a half-life of 4.5 billion years, the use of DU would constitute long-term damage. Whether it would also satisfy the widespread and severe requirement would depend on the circumstances. The use of over 10000 DU rounds by the US troops in 2003, which resulted in the contamination of over 300 sites in Iraq for example, would cross the thresholds. However, the rule is only contained in Art.35(3) of AP I and the customary basis of this rule is perhaps the weakest amongst the three as there is a complete absence of comparable rules under AP II.


The lack of any treaty regulating the use of DU and the absence of applicable rules under the existing IHL treaties have created a legal lacuna concerning the use of DU in NIAC. As most armed conflicts in the contemporary world are non-international in nature with certain cross-border elements, it raised the question of whether a common international framework to regulate DU in NIAC was required. More research is indeed needed to understand the adverse effects resulting from the use of DU so as to create a general consensus to regulate or prohibit its use.


Add a comment