In March, in the small middle eastern country of Yemen, a long-running political crisis escalated into all-out conflict. At the request of the Yemeni government an international coalition led by Saudi Arabia began air strikes across Yemen against Houthi rebels. For ordinary Yemenis, the consequences have been devastating.

As a recent report, State of Crisis: Explosive Weapons in Yemen (pdf) documents, more than 2,200 civilian deaths had been registered by September. “The intensity of explosive violence in the country has meant that more civilian deaths and injuries from explosive weapons were recorded … during the first seven months of 2015 than in any other country in the world.”

Picasso’s famous painting, inspired by the bombing of Guernica, June 1937, during the Spanish civil war. Photograph: Barney Burstein/Corbis

All parties to the conflict are using heavy explosive weapons across the country, the majority of them unleashed on populated areas, from the capital Sana’a in the north to Taiz and the port city of Aden in the south, with Isil and al-Qaeda in the Arabian Peninsula adding to the mayhem. The proportion of deaths and injuries that are civilian in populated areas of Yemen is overwhelming: from air-launched explosive weapons – 93%; from ground-launched explosive weapons – 94%; from improvised explosive devices – 97%.

But although the report by Action On Armed Violence (AOAV) and the UN Office for the Coordination of Humanitarian Affairs (OCHA), is specifically focused on the use of explosive weapons in Yemen, the issues it raises have even broader, and more worrying implications. This is, after all, but the latest instance of a horrifying trend in twentieth and twenty-first century warfare, with Guernica (1937) during the Spanish Civil War, one of the earliest, if not the first, massive air force bombings of a defenceless civilian population. During the second world war there was the London blitz, Rotterdam, the carpet-bombing of German cities (Dresden leaps to mind); the incendiary bombing of Tokyo, Kobe, Osaka and other Japanese cities, with massive civilian loss of life in the months preceding Hiroshima and Nagasaki.

January 10, 1995; a Chechen fighter taking cover across from the presidential palace, destroyed by Russian artillery bombardments. Photograph: Michael Evstafiev/AFP/Getty Images

After the war debates ensued: were such massive, targeted civilian deaths justified? Collectively, the world took a step back. Surely, protection of civilians from harm must be a priority, even during armed conflict? From this reflection emerged the Geneva Conventions of 1949, shortly after the adoption of the Universal Declaration of Human Rights by the United Nations the year before. Additional protocols to the Geneva Conventions followed in 1977 and 2005, while the world has adopted and ratified a range of international human rights conventions that have sought to assure the protection of civilians and their rights - and that sovereign states not just demand respect for their sovereign rights, but also meet their obligations to protect and safeguard the human rights of their citizens.

So today we must be living in a more humane world, right? Well, no. While we now have a wide array of international human rights and humanitarian standards, they are frequently flouted with impunity. Let’s look at a few examples of the use of what the AOAV-OCHA report calls “explosive weapons with wide-area affects” in the last quarter-century.

In 1990 the Sri Lankan city of Jaffna was destroyed by aerial bombardment by government forces during the civil war, killing and wounding many Tamil civilians. Civilian survivors’ reported barrel bombs – made infamous today in Syria by Assad’s forces – being dropped on Jaffna. Oil drums packed with explosives, killing civilians indiscriminately and in large numbers.

Between 1994 and 1995, the Russians bombed the Chechen capital, Grozny, in what was then the heaviest bombing campaign in Europe since the second world war, with heavy civilian casualties. Grozny was bombed again in the 1999-2000 winter siege: most deaths and injuries were civilian; the capital was devastated by tank and aerial bombardment, ballistic missiles, fuel-air explosives, and thermobaric weapon warheads. These last are particularly horrific. First used in Vietnam, they have the longest blast wave and destructive force of any known weapon, destroying unreinforced buildings, killing and injuring people by inflicting severe burns, rupturing the lungs and internal organs, causing suffocation and severe concussion. And yes, Assad is alleged to have used these in Syria, too.

In 2014 Hamas, Islamic Jihad and other militant groups fired thousands of rockets and mortars towards Israel. The Israeli Defence Force responded with bombardment that flattened densely populated swathes of Gaza; some 2,200 Gazans were killed and approximately 10,700 wounded - mostly civilians, including more than 3,300 children.

Dresden, 1952: people working on the removal of debris in front of the ruins of the Frauenkirche, which was reduced to rubble during Allied bombings. Photograph: AFP/Getty Images

The list goes on: Afghanistan, Iraq, Bosnia, Libya, Ukraine … Syria. As part of what the UN has called a “relentless campaign of bombardment and artillery shelling … unlawful attacks in 12 of 14 governorates”, the Assad regime has rained barrel bombs – some filled with chlorine gas – on cities with complete impunity since the start of the civil war in 2011 with at least 225,000 deaths to date, most of them civilian.

But now this pattern of harm from explosive weapons is emerging as a key concern in the protection of civilians. UN secretary-general Ban Ki-moon has repeatedly called on member states to recognise and address this critical humanitarian issue and has urged parties to conflict to refrain from using explosive weapons in populated areas in particular. He has called for the UN Security Council to do the same. AOAV and OCHA are urging parties to conflict to share national policies and practices relating to the use of explosive weapons, collect information on the civilian harm that they cause, recognise the rights of victims and survivors and ensure that assistance is gender- and age-sensitive.

A Syrian man cries as he sits on the rubble of a building following a reported barrel-bomb attack by government forces on August 11, 2014. Photograph: Baraa Al-Halabi/AFP/Getty Images

But in an increasingly multipolar world, where actors exploit civil wars to pursue their own proxy wars, who will heed AOAV and OCHA’s call? In a world in which the five permanent members of the UN security council, together with Germany, are among the main exporters of arms, is there an alternative to cynicism? We have to hope so.

The International Committee of the Red Cross (ICRC) and the government of Switzerland have for the last few years undertaken a major international consultation process on how to improve compliance with international humanitarian law. The ICRC will present the results of the consultations, as well as its recommendations, to the 32nd international conference of the Red Cross and Red Crescent in December. Let us hope that ICRC’s recommendations to improve compliance will be heeded, adopted and applied by states and non-state parties alike.

In May 2016, the world humanitarian summit will review the humanitarian system. It should also squarely confront failures in the political domain to protect civilians in situations of armed conflict – failures by parties to conflict, but also failures by the international community (the UN security council in particular) to agree on the rigorous application of international norms, to demand compliance and to bring perpetrators of violence against civilians to account. At the moment this is not happening. Impunity reigns. World leaders cannot continue to develop international norms for the protection of civilians and then blithely disregard them.

State of Crisis: Explosive Weapons in Yemen report is a stark reminder of the willful brutality of our world, of the casual use of explosive weapons whose victims are predominantly civilian. Is it only occasionally that photos of young children like Alan Kurdi will rouse us to action? I hope not. Our fellow citizens caught up in the horror of armed conflict deserve better.

Nigel Fisher is former assistant secretary-general of the United Nations and former leader of international humanitarian operations in the Middle East for the Syria crisis, in Afghanistan and Haiti.

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