Russia’s TOS-1A is a truly awful weapon of war for many reasons: The TOS-1A is a Multiple Launch Rocket System (MLRS) used for firing surface-to-surface, thermobaric artillery. Its warhead is known as a “vacuum bomb,” which, upon explosion, disperses aerosolized chemicals. These chemicals are then ignited, resulting in a huge explosion, with the large chemical fireball creating such a high-pressure shock wave that is creates a pressure vacuum. This vacuum then pulls air in from around the explosion both creating a “ripping effect” and making the flames larger and hotter. This “ripping effect” can be devastating to humans in the area, creating deadly trauma to internal organs.
Part of what makes the weapon effective, however, is that prior to detonating its chemical cloud, the chemicals themselves, gaseous as they are, are able to surround and make vulnerable even hardened targets. The temperature of the ensuing fireball ranges from 2,500 to 3,000° Celsius.
Despite not being banned under international law, the weapon is quite gruesome and raises questions surrounding the targeting of civilians, especially if it is being used in places where military infrastructure is embedded with civilian infrastructure.
Since developed in the Soviet Union in the 1980’s and 1990’s, not much has changed with the TOS-1 system. The 24 rocket launchers are loaded on a T-72 tank chassis, making the weapons mobile. The most recent variant, the TOS-1A, extends the weapon’s range from 6 kilometers to 10 kilometers. It also contains an upgraded ballistic computer.
The TOS-1 was first used by the Russian military in its campaigns in Chechnya. It has since been used by the Iraqi military in 2014 in campaigns against the Islamic State, as well as Syrian and Russian counterinsurgency campaigns. In addition to reports of Russia employing the weapon to devastating effect in Ukraine, the TOS-1A was also used in the Nagorno-Karabakh conflict between Armenia and Azerbaijan in 2020.
It is still unclear what Russia’s use of the weapon in Ukraine will yield. Many commentators have noted that its destructive capabilities can make avoiding civilian targets difficult if not impossible. Not unlike Russian use of cluster munitions, the problem is with discrimination between combatants and non-combatants, a key feature of the laws regulating the conduct of war.
However, with its high capacity for clearing well dug-in forces, it is unlikely Russia and others possessing the TOS-1A will give it up anytime soon. Despite its devastating impact, this weapon is unlike cluster munitions in that it doesn’t leave future additional danger in its footsteps. It is just one huge, oxygen-sucking explosion.
Alex Betley is a recent graduate of the Tufts University Fletcher School of Law and Diplomacy where he was an International Security Studies Civil Resistance Fellow and Senior Editor with the Fletcher Security Review