Are Thermobaric Weapons Illegal? Putin Accused of Vacuum Bombing Ukraine

Ukraine's ambassador to the United States and human rights groups on Monday accused Russia of using a thermobaric weapon, also known as a vacuum bomb, during a recent attack in Ukraine.

"They used the vacuum bomb today," Markarova told reporters after speaking with members of the U.S. Congress one Monday. "The devastation that Russia is trying to inflict on Ukraine is large."

There has been no official, independent confirmation that thermobaric weapons have been used by Russia against Ukraine, but CNN reported one of its teams saw a Russian thermobaric rocket launcher near the Ukrainian border on Saturday. Amnesty International and Human Rights Watch have also stated Russian forces appeared to have used the controversial weapon, and Amnesty accused the invading troops of using banned closer munitions during an attack that hit a preschool with civilians inside. Some have questioned the legality of using such weapon, even in wartime situations.

Thermobaric launchers
Ukraine's envoy to the U.S. claimed Russia forces used a thermobaric weapon, aka a vacuum bomb, in the Ukraine. Above, thermobaric rocket launchers are seen upon vehicles during a military parade in Red Square on June 24, 2020, in Moscow. (Photo by Ramil Sitdikov - Host Photo Agency via Getty Images

What are thermobaric weapons?

A thermobaric weapon, also called a vacuum bomb or fuel-air explosive (FAE), is a two-stage munition. A charge first distributes an aerosol from a carbon-based fuel to tiny metal particles. Next, a second charge creates a fireball-like ignition, generating a vacuum that sucks up oxygen in the surrounding vicinity.

What are the effects?

The result of the bomb's high-temperature explosion is said to be a blast that is capable of vaporizing human bodies.

A 1993 study by the U.S. Defense Intelligence Agency entitled "Fuel-Air and Enhanced-Blast Explosive Technology—Foreign" described the deadly effects of thermobaric weapons.

"The [blast] kill mechanism against living targets is unique—and unpleasant," the study said. "What kills is the pressure wave, and more importantly, the subsequent rarefaction [vacuum], which ruptures the lungs.… If the fuel deflagrates but does not detonate, victims will be severely burned and will probably also inhale the burning fuel. Since the most common FAE fuels, ethylene oxide and propylene oxide, are highly toxic, undetonated FAE should prove as lethal to personnel caught within the cloud as most chemical agents."

Why are thermobaric weapons controversial?

More than anything, it's the devastating and agonizing effects of the explosives that have led human rights groups to speak out against their use, especially when the bombs are dropped on people.

Sean Spoonts, editor-in-chief of, told Newsweek in detail about the effects the weapons have when used on humans.

"You have a huge pressure wave when it goes off, which is intensely hot and scorches and burns everything that's within the cloud or a close range to it," Spoonts said. "Then there's a tremendous near-vacuum created as the air tries to rush in that literally collapses your lungs and explodes your eardrums out and can pop your eyeballs out of your head."

He continued, "You're going to fall to the ground and be incapacitated but not dead. You might have a minute or two of suffocating to death while your lungs collapse."

The explosion itself is not the only way these devices can kill you either, according to Spoonts.

"The chemicals that are used to set it off are essentially a chemical weapon because they're toxic," he said. "So, if you were in this huge cloud that might be a 200 meters across depending upon the size of the bomb—it could be 600, 700 feet across—it's probably going to kill you if it doesn't detonate, because these toxic chemicals would likely be fatal to you."

Have thermobaric weapons been banned?

Vacuum bombs are not technically illegal and can be used in certain battle situations. However, the use of fuel-air explosives on civilians is considered a breach of the Geneva Convention, which drafted guidelines for how weapons can be used during war in regards to human populations. Nongovernmental watchdog groups have also long condemned the use of thermobarics for the indiscriminate nature of the destruction it can cause.

White House press secretary Jen Psaki was asked during a Monday press briefing if the Biden administration was aware of reports of vacuum bombs being used in Ukraine and if the use of the weapons would be a war crime.

"It is [aware]—it would be," Psaki replied. "I don't have any confirmation of that. We have seen the reports. If that were true, it would potentially be a war crime."

She added, "Obviously, there are a range of international fora that would assess that. So, certainly, we would look to that to be a part of that conversation."

If a country intentionally uses the bombs on civilian populations, charges of war crimes could be brought up under the Hague Conventions of 1899 and 1907.

Has Russia used thermobaric weapons before?

There have been reports of Russia using the weapons for decades, dating back to the Sino-Soviet border conflict and against the Mujahideen in Afghanistan. More recently, Russia reportedly used vacuum bombs against the Dagestani village of Tando, Russia, in 1999.

A 2000 report from the Human Rights Watch also detailed Russia's suspected use of thermobarics on the Russia republic Chechnya. The report said the deployment of such weapons in Chechnya posed "important humanitarian implications."

Russia is not the only country to have used vacuum bombs, though. Spoonts told Newsweek that Germany invented the explosives during World War II. The United States itself also has a history with thermobarics going back to the Vietnam War.

The U.S. even recently used thermobaric bombs on an ISIS cave complex in Afghanistan in 2017. The extremely powerful explosive detonated there was nicknamed "Mother of All Bombs." Russia, meanwhile, tested an even larger thermobaric weapon that was dubbed the "Father of All Bombs" in 2007. That device has been called the biggest non-nuclear explosive device in the world.

"The problem is, the bigger it is, the further away you need to be away," Spoonts said of these enormous explosives. To make even more effective use of thermobaric technology, he said militaries have made thermobarics in the size of artillery shells and even grenades.

The thermobaric bombs that would have been used in Ukraine were most likely missiles in large box launchers attached to a tracked vehicle, Spoonts said.

Newsweek contacted the Russian embassy in Washington, D.C., for comment but did not hear back in time for publication.

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