U.S. Marines and paratroopers who could be sent into combat in Iran are conducting CBRN (Chemical, Biological, Radiological, and Nuclear) safety drills at their bases in Europe and aboard ship as they sail to the Middle East.

The National reported on Friday that advance units of paratroopers from the 82nd Airborne Division, flown from America to Europe to prepare for possible deployment in Iran, have been supplied with “detection systems, gas masks and protective ‘Mopp’ coveralls.”

MOPP (Mission Oriented Protective Posture) suits are essentially hazmat suits for soldiers. MOPP alerts are issued in various levels requiring heavier amounts of protective gear as the anticipated hazard condition grows more serious.

Retired U.S. Marine Corps officer Jonathan Hackett told The National that the 31st Marine Expeditionary Unit is “practicing CBRN drills on deck as we speak” as they head for the Middle East aboard the amphibious assault ship USS Tripoli, a relatively small aircraft carrier that transports Marines and their support equipment to conflict zones.

“The CBRN unit can also be scaled up in size, but the conventional marine forces will have their CBRN gear and be drilling on it, with 15 seconds to get mask and Mopp on when someone shouts ‘Gas, gas, gas,’” he explained.

Military analysts and hazardous materials specialists said there are several potential hazard scenarios in Iran, including damage to Iran’s Bushehr nuclear power plant, Iran’s elusive stockpile of near-weapons-grade uranium, inadvertent breaches of bunkers where Iran stores chemical weapons left over from the Iran-Iraq War in the 1980s, and the worst-case scenario of a desperate Islamic Revolutionary Guard Corps (IRGC) loading chemical or biological payloads into its missiles.

Iran also helped Syrian dictator Bashar Assad develop his chemical weapons, and some analysts fear Iran might have reclaimed some of Assad’s inventory after he was driven from power in December 2024.

“They may well still be on bases somewhere, but it’s stronger than hearsay that some of these chemical weapons actually moved eastwards and are now either in Iraq or Iran,” chemical weapons specialist Lennie Phillips told The National.

Iran is known to have conducted research into biological weapons during the Iran-Iraq War, even though Iran signed the Biological Weapons Convention in 1973, six years before the revolution that brought the current Islamic Republic regime to power.

Iran’s bioweapons program seemed especially interested in developing anthrax, reportedly conducting much of the work in underground Syrian laboratories during Assad’s reign.

The U.S. State Department warned in 2019 that Iran was still conducting “research and development of biological agents and toxins for offensive purposes.”

In 2025, the Office of the Director of National Intelligence (ODNI) upgraded this warning to say that Iran “very likely aims to continue R&D of chemical and biological agents for offensive purposes.”

Chemical and biological weapons research is especially easy to conduct under the guise of “dual-use” technologies that could also be employed for harmless or productive research, such as developing industrial chemicals or medicines. As the ODNI pointed out, chemical and biological payloads are much easier to load into ballistic missiles than nuclear warheads.

Chemical warfare specialist Hamis de Bretton-Gordon told The National that the United States, and perhaps the rest of the world, should draw a firm “red line” against Iran using weapons of mass destruction, no matter how desperate the regime becomes.

“There needs to be a Trump red line, which means something, which would be the most effective way of stopping these weapons being used. My concern is that if the Iranians run out of road, what do they do then, because this is in their psyche from the Iran-Iraq War,” Bretton-Gordon said.