Explosive Remnants of War

Explosive remnants of war (ERW) is a legal term of art covering two categories of leftover ordnance: unexploded ordnance (UXO), meaning munitions that were fired, dropped, or launched but failed to detonate as intended, and abandoned explosive ordnance (AXO), meaning munitions left behind by an armed force, often in caches or depots, without being used. The category typically includes artillery shells, mortar rounds, grenades, aircraft bombs, rockets, and submunitions from cluster weapons, but excludes anti-personnel and anti-vehicle landmines, which are governed by separate instruments.

The governing instrument is Protocol V to the Convention on Certain Conventional Weapons (CCW), adopted in Geneva on 28 November 2003 and entering into force on 12 November 2006. Protocol V obliges parties to a conflict to:

• clear, remove, or destroy ERW in territory under their control after hostilities end;
• record and share information on munitions used, to facilitate clearance;
• take feasible precautions to protect civilians from ERW;
• provide assistance, including risk education and victim assistance, where appropriate.

Cluster munition remnants are additionally regulated by the Convention on Cluster Munitions (Dublin, 2008; entry into force 1 August 2010), which imposes stricter clearance and victim assistance obligations on its states parties.

ERW disproportionately harm civilians long after fighting ends. Children are frequent victims because unexploded submunitions and shells can resemble toys or scrap metal. Contaminated land also blocks agriculture, displaces returnees, and slows reconstruction. Major clearance operators include national mine action centres, the UN Mine Action Service (UNMAS), the Geneva International Centre for Humanitarian Demining (GICHD), and NGOs such as the HALO Trust, Mines Advisory Group (MAG), and Norwegian People's Aid. Annual data on casualties and clearance is compiled by the Landmine and Cluster Munition Monitor.