Images of children fleeing a napalm attack during the Vietnam War remain among the most haunting reminders of the brutality of modern conflict.

The iconic 1972 photograph of nine-year-old Kim Phuc running naked after her clothes were burned by napalm shocked the world and became a powerful symbol of the human cost of war.

More than five decades later, such images continue to shape global debates about the use of certain weapons in conflict. Recently, Human Rights Watch accused Israel of using white phosphorus munitions over residential areas in southern Lebanon, an allegation that has once again brought attention to weapons whose use is restricted or banned under international humanitarian law.

White phosphorus itself is not completely prohibited. Militaries around the world use it for smoke screens, illumination and signalling. However, international law forbids using incendiary weapons like white phosphorus in areas where civilians are present because of the severe injuries and uncontrollable fires they can cause.

The controversy highlights a broader framework of international conventions designed to limit the suffering caused by warfare.

Over the decades, the global community has identified several categories of weapons considered excessively cruel or indiscriminate, leading to treaties that either ban them outright or strictly regulate their use.

One of the most widely condemned categories is chemical weapons. These include toxic agents such as sarin, mustard gas, and chlorine that can kill or incapacitate people through chemical reactions in the body. Their devastating impact during World War I led to global efforts to prohibit them, culminating in the 1993 Chemical Weapons Convention, which bans their development, stockpiling, and use.

Biological weapons are similarly outlawed. These weapons deploy pathogens such as bacteria, viruses or toxins to spread disease among humans, animals or crops. The Biological Weapons Convention of 1972 prohibits countries from producing or possessing such agents for warfare.

Other banned or restricted weapons include cluster munitions, which disperse hundreds of small explosive bomblets over wide areas. Many of these fail to explode immediately and remain dangerous for years, often harming civilians long after conflicts end. The 2008 Convention on Cluster Munitions prohibits their use, production and transfer among signatory nations.

Anti-personnel landmines are another widely condemned weapon. Designed to detonate when triggered by human contact, they frequently injure civilians and remain buried for decades after wars conclude. The 1997 Ottawa Treaty bans their production, use and stockpiling.

Some prohibitions target weapons designed to cause unnecessary suffering. Expanding or “dum dum” bullets, which widen on impact and inflict severe injuries, were banned under the Hague Convention of 1899.

Modern technological developments have also prompted new restrictions. Blinding laser weapons, intended to permanently damage eyesight, are banned under a 1995 United Nations protocol.

International humanitarian law also prohibits weapons that produce fragments undetectable by X-rays, as well as certain types of booby traps disguised as everyday objects such as toys or food items.

Incendiary weapons like napalm fall under additional restrictions. While not entirely banned, international law prohibits their use against civilians or near populated areas due to the devastating burns and fires they cause.

Although such treaties cannot eliminate war, they represent attempts by the international community to limit its worst excesses. By restricting particularly destructive weapons, these agreements aim to reduce suffering and protect civilians caught in the crossfire of armed conflicts.