The deployment of the M825 WP projectile in Fallujah (2004) and Gaza (2009) makes them relevant case studies for the analysis of the effects of air-burst white phosphorus munitions in urban environments, as conducted throughout this report.

An M825 WP round will distribute its payload of 116 burning WP wedges within an elliptical perimeter, whose area is between 5,000 and 30,000 m2, depending on how the round has been fired. This Coverage Area can therefore be larger than a whole Manhattan block. In a city of comparable density to New York or Gaza, it corresponds to the area inhabited on average by 50-300 people, and by over a 1,000 people in specifically dense zones.

There are numerous variables that influence the trajectory of each single WP wedge. The precise point of burst of the projectile in the air, the initial distribution of the wedges at burst, the meteorological conditions, the type of surface first impacted in the urban fabric, the potential for a ricochet effect, as well as others. Most of these variables are not under the control of the armed forces deploying the M825 WP projectile. Therefore:

1. The exact distribution and trajectory of each WP wedge must be considered random.
2. Any surface, object or person situated directly under the burst of a M825 WP round is at risk of being hit by a WP wedge.

The diversity and density of structures and objects that is characteristic of any urban environment must be taken into account when evaluating the incendiary effect that can be expected when white phosphorus munitions are to be deployed within urban contexts. The chances for burning white phosphorus to react with various combustible materials present in the urban fabric, and therefore to function as an ignition source, are largely increased compared to a deployment in open battlefield. Moreover, the fires that may consequently break out can affect a large number of civilian persons and objects.

The precise effects of an M825 WP round deployed in an urban environment are impossible to predict with any accuracy, however the study of the interplay of identifiable patterns of behavior between the projectile and a typical residential urban fabric lead to the following conclusions:

1. Because of the number of wedges (116) ejected by each round, for any round there is a high probability (above 95%) that at least one wedge will hit a window, and possibly penetrate into an inhabited interior space. Furthermore, there is a consequent high probability that fire will break out in this interior space.
2. There is a high probability (above 95%) that some wedges will hit exterior spaces such as streets and public squares. This in turn raises a real possibility that anyone and anything present at that moment may be hit. The number of wedges that can impact a public space vary according to the type of urban environment impacted.

For all the above reasons, and regardless of the primary motivation for the military use of airburst white phosphorus munitions, their deployment in urban environments puts the civilian population in these areas at great risk of death or injury, and the civilian objects and environment at an equal risk of destruction, damage, or contamination by a flammable and toxic substance. Moreover, because of the numerous random variables at play that govern the behavior of airburst white phosphorus, this risk cannot be managed nor controlled by the armed forces that deploy these munitions.