In November 2022, eighty-three States endorsed the Political Declaration on Strengthening the Protection of Civilians from the Humanitarian Consequences Arising from the Use of Explosive Weapons in Populated Areas (Political Declaration). The Political Declaration is a new and significant development in the long-standing and ongoing efforts to protect civilians from the use of explosive weapons in populated areas – an issue which has been of growing concern for a number of states, the United Nations, the International Committee of the Red Cross and civil society for more than a decade.

The use of explosive weapons in populated areas has been documented to result in widespread civilian deaths and injuries as well as longer-term harm to civilians resulting from damage to or the destruction of hospitals, water and sanitation systems and electrical power grids. Although less researched, the use of explosive weapons in populated areas also plays a prominent role in damaging and destroying the environment in situations of armed conflict.

This article examines the potential of the new Political Declaration for strengthening the protection of the environment. An express reference to the environment, and the impact of explosive weapons thereon, exists only in the Declaration's preamble, but the lack of express references to the environment in the Declaration's operative commitments does not mean it lacks potential as a tool for strengthening the protection of the environment. On the contrary, the preambular reference provides an important basis on which to argue that the armed forces of endorsing States must consider the protection of the environment in their efforts to implement a number of the Declaration's key operational commitments.

During an armed conflict, the use of explosive weapons with wide area effects in populated areas has a devastating impact on civilians. Less visible than the direct effects of explosive weapons, but equally devastating, are the reverberating effects of the use of explosive weapons in populated areas. While there is growing consensus that parties to an armed conflict are legally obliged to take into account the reasonably foreseeable reverberating effects of an attack, particularly for the purposes of the rules on proportionality and precautions in attack, the precise scope of this obligation remains unclear. After setting out the legal arguments in support of the position that reasonably foreseeable reverberating effects must be taken into account, this article goes on to examine how such effects should be evaluated and how they must be avoided or minimized.