In recent weeks, wildfires have ravaged Europe amid record-breaking heat and drought. These fires posed an immediate threat to life, forcing the evacuation of over 300,000 people across France, Spain and Portugal. Rivers across Europe have also hit record low water levels .
Author
- Nicole Townsend
Lecturer in War Studies, UNSW
These developments have highlighted a deadly legacy of past conflict: unexploded bombs and other munitions.
Fires in southern France exposed a previously unidentified cache of 400 French and German shells from the second world war. The ammunition detonated in the heat of the fire, forcing authorities to clear the area before residents could return.
Dropping water levels have also revealed unexploded munitions in the Netherlands , Hungary , and Slovakia .
But fires and drought in Europe are only the latest reminder of an enduring problem that affects millions worldwide.
Explosive remnants of war
Since the first world war, numerous conflicts have ravaged the world, scarring the landscape and littering battlefields with unexploded, abandoned, or otherwise discarded munitions.
Known as explosive remnants of war (ERW), unexploded munitions posed a continuing threat to an estimated 100 million people across 60 countries in 2025.
ERW includes two categories of ordnance. The first is unexploded ordnance (UXO), which are explosive weapons that failed to detonate when they were first deployed. The second is abandoned explosive ordnance (AXO), left behind after a conflict.
The bomb located in Budapest would be classed as an unexploded ordnance, but the cache that detonated amid the Gironde fires appears to fall into the latter category.
Both can include a variety of different munition types, from artillery shells and mortars to grenades and large bombs dropped from aircraft.
Beyond these, landmines are another key explosive contaminant. Landmines are not legally classed as explosive remnants of war because they are deliberately placed during conflict. Yet their extensive use in conflicts globally makes them one of the key explosive contaminants of conflict.
What countries are affected?
After the second world war, European countries worked quickly to remove the landmines that had been put in place during the conflict. In the Netherlands alone, almost 1.4 million mines were cleared between May and November 1945. A similar number were laid by German forces in Denmark, which cleared most of its known minefields by the end of 1945 .
As of 2024, the United Kingdom, France, Germany and Denmark are all classed as having completed mine clearance.
Yet globally at least 57 states and other areas remain contaminated by antipersonnel landmines as of October 2025. Many of these are in Africa, the Middle East and Asia.
Among the countries most contaminated by landmines are Afghanistan, Bosnia and Herzegovina, Cambodia, Ethiopia, Iraq, Türkiye, Ukraine, and Western Sahara.
Some were laid during the second world war. This includes minefields placed by both Allied and Axis forces across Algeria, Egypt, Libya, Morocco and Tunisia as part of the North Africa campaign .
Subsequent conflicts also led to extensive minefields being laid. For example, the Vietnam War left nearly 20% of the country contaminated by landmines - an area the size of Tasmania . Decades of conflict left neighbouring Cambodia heavily contaminated , while the Iran-Iraq War left millions of unmarked mines littering the border regions.
Identifying the exact number of countries contaminated by remnants of war is more difficult, with any place that has seen conflict potentially affected. While a country can be deemed free of landmine contamination, it may still be faced with the risk of remnants of war.
In the first world war alone, more than 700 million shells and mortar bombs were fired across the Western Front . An estimated 140 million of these failed to detonate. Each year, Belgian and French farmers routinely collect these and other UXO as part of what is known as the Iron Harvest .
Closer to home, remnants of war from the second world war continue to kill and maim those who encounter them. This includes an Australian killed while handling a mortar shell in the Solomon Islands, with several UXO also located across Darwin in recent years.
Broader implications
According to the Land Mine Monitor , more than 6,000 people were killed or injured by landmines and remnants of war in 2024. Most of these casualties were civilians, with reported casualties spanning no fewer than 52 countries.
The primary danger relates to the detonation of landmines and remnants of war, but the threat they pose goes beyond safety and physical harm.
Studies have shown their presence can restrict access to arable lands , impact soil and water quality , affect food security and diversity, and stunt economic development .
These risks are exacerbated by increasingly frequent and extreme weather and natural disasters driven by climate change. Flood events can relocate and unearth landmines and other remnants, while wildfires can detonate them unexpectedly.
Meanwhile, dropping water levels in rivers and lakes can expose civilians to greater risk of harm by allowing access to contaminated riverbeds that would otherwise be inaccessible.
This is also not a historical issue. Anti-personnel mines are still being used in conflicts such as the war in Ukraine , and several European nations have withdrawn from a treaty designed to prohibit their use.
Military-led operations are working to clear remnants of war in many places, including Pacific island countries. However, these recent events are a reminder of the ongoing threat of remnants of war and landmines, and the need for an integrated approach that recognises and responds to the broader risks and challenges they pose.
Nicole Townsend does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
