Throughout history, mankind has evolved through numerous technological advancements—particularly in war. The evolution of weaponry has taken place rapidly from the 1800s until now, with some weapons becoming so deadly that they are forbidden or have conventions not to use.

Today, biological weapons and most chemical weapons are prohibited, with nuclear weapons development extremely monitored. However, some of the deadliest weapons in war that have been used in history are not forbidden, despite the controversies they may bring.

Napalm

Napalm is a torch of sticky white gel and a petrochemical, sometimes petrol or diesel. Fused, the weapon can cause a widespread fire chain that can cook a human body.

Incendiary uses of napalm would take place in the late stages of WWII, targeting key logistical cities of Germany and Japan. During the Korean War, napalm was used frequently to halt the human wave tactics of North Korea and China—albeit the bombings came at a price of massive civilian life lost.

The effects of napalm and the grizzly toll of the torch came during the Vietnam War. As the Vietnam War was televised, the general public saw some of the most horrific effects of firebombing.

A plethora of Vietnamese civilians, in the then separated north and south, suffered lasting burn effects along with US troops caught by friendly fire. Napalm is prohibited against civilian use, but the Convention on Certain Conventional Weapons (CCW) does not outright ban the use on military targets.

“Napalm Girl” then and now from Nick Ut’s original, uncropped version of “Napalm Girl” Phan Thi Kim Phúc with ARVN soldiers and several journalists.

White Phosphorus

White phosphorus, another incendiary munition, is primarily used for illumination for frontline forces. The torch is also extremely harmful to the human body, leaving horrific burn marks and often excruciating pain to those who touch it.

Though white phosphorus was used extensively during the world wars and Vietnam, the substance would gain prominence in modern warfare as several conflicts showed the horror of incendiary munitions.

During the US invasion of Iraq, white phosphorus was used by US forces against al-Qaeda in the Battle of Fallujah. Controversies arose over the potential use of civilians by coalition forces during the war.

In other engagements in the Middle East, Israel has been accused of using the substance in prior wars in Gaza and Lebanon, and the Turkish military used it against Kurdish militias in Syria. According to the Geneva Conventions and CCW, white phosphorus is not banned in war as long as it is not purposely used against civilians.

Use of white phosphorus by Israel in Lebanon in 2023 via AFP

Cluster Munitions

Cluster munitions are surface-dropped explosive weaponry that releases/ejects smaller shrapnel projectiles in a certain radius. Due to the munitions releasing small bomblets and having various degrees of dud rates, cluster bombs pose great risks to civilians.

Cluster munitions have been used in wars such as the Vietnam War, Lebanon, Soviet-Afghan War, Chechnya, Iraq, and the Karabakh wars. The US military currently uses its variation of cluster munitions, commonly known as the dual-purpose improved conventional munition (DPICM).

Currently, the Russian and Ukrainian militaries are using cluster munitions during their ongoing war. However, it is important to distinguish the uses between both countries.

Russian forces are using cluster munitions against civilians, with reported usage in densely populated cities such as Kharkiv. Ukraine is using it solely on Russian troop positions away from civilian vicinity as promised to the United States, which is supplying Kyiv with DPICMs.

Cluster munitions do not fall under the Geneva Convention, save for illegal use on civilians and population centers. Instead, they fall under the Convention of Cluster Munitions, which only has 100 signatories out of the 200-plus nations of the world.

Depleted Uranium Shells

Depleted uranium (DU), defined by Reuters, is a dense by-product of left-over uranium that was enriched. Though still having some forms of radiation, the isotopes are far less than highly radioactive material.

Fitted for military use outside of nuclear weapons, primarily in artillery shells and tank rounds. Only a handful of countries have DU rounds in their inventory, such as the United States, Russia, the UK, France, Germany, the Netherlands, China, Japan, South Korea, South Africa, and Singapore.

Depleted uranium rounds were used during the 1991 Gulf War, the NATO bombing of Serbia, and the 2003 US-led invasion of Iraq. Serbia and some reports have complained about the use of DU and that they correlated to cancer spikes, though a link through an international inquiry has not yet been found.

Debates arose over sending DU rounds to Ukraine as the British Challengers and American Abrams were fitted for the munitions. As of today, Ukraine has used the tanks and the rounds, but no such reports of radioactive activity from the munitions have arisen.

The Geneva Conventions do not ban depleted uranium munitions, but usage against civilian populations is prohibited.

Despite some of the most brutal weapons being used in warfare, various weapons with gruesome side effects are not banned today. However, major military regions and superpowers should work to mitigate after-effects and usage near civilian populations as much as possible.