But this type of warfare also gives the United States a chance to learn about the latest Russian technology.

American troops deployed in Syria are increasingly having to defend themselves against Russian jamming devices—electronic attacks with potentially lethal consequences, according to U.S. military officials and analysts.

Officers who have experienced the jamming—known as electronic warfare—say it’s no less dangerous than conventional attacks with bombs and artillery. But they also say it’s allowing U.S. troops a rare opportunity to experience Russian technology in the battlefield and figure out how to defend against it.

U.S. Army Col. Brian Sullivan described one recent episode to reporters at the U.S. Defense Department last week. He said his troops had encountered a “congested … electronic warfare environment” while fighting in northeastern Syria during their nine-month deployment, which stretched from September 2017 to May 2018.

“It presented challenges to us that we were able to successfully contend with, and it gave us an opportunity to operate in an environment that can’t be replicated anywhere at home station, including our combat training centers,” Sullivan said.

“It’s a great opportunity for us to operate particularly in the Syrian environment where the Russians are active.”

Sullivan, whose unit has since returned from deployment to Iraq, Syria, Afghanistan and Kuwait, did not say how the jamming affected his team. But experts in electronic warfare say an attack can impair communications equipment, navigation systems, and even aircraft.

“All of a sudden your communications won’t work, or you can’t call for fire, or you can’t warn of incoming fires because your radars have been jammed and they can’t detect anything,” said Laurie Moe Buckhout, a retired Army colonel who specializes in electronic warfare.

“[It] can be far more deadly than kinetics simply because it can negate one’s ability to defend one’s self,” she said.

U.S. troops fighting abroad since the 9/11 attacks—in Iraq, Afghanistan, and elsewhere—have faced mostly nonconventional forces and have not had to contend with electronic warfare.

But Syria is a different arena. Conventional forces from Russia, Iran, and occasionally Israel have operated in the country, as well as the Syrian army itself.

In this complex, congested environment, the concern is that a miscommunication or inadvertent encounter could quickly escalate into a full-on war.

Daniel Goure, an expert on national security and military issues at the Lexington Institute, says Russia’s new electronic warfare systems are sophisticated. They can be mounted on large vehicles or aircraft and can impair targets hundreds of miles away.

“The trouble with [electronic warfare] broadly speaking is it can really screw with your picture of the battle space, your operating picture, and that can lead to really horrendous mistakes,” Goure said.

“This is escalatory. There is no question about it,” Goure said.

The U.S. campaign in Syria targets the Islamic State. But U.S. troops have occasionally had contact with Russian forces. Russian aircraft frequently fly within close range of U.S. fighter jets, with one near-collision occurring last December. And U.S. troops in February engaged in a bloody four-hour battle against pro-regime forces in eastern Syria, including private Russian mercenaries.

Analysts say Russia is increasingly using Syria as a testing ground for new electronic weapons, which Moscow developed over the past 10 to 15 years in response to NATO’s dominance in conventional weaponry. Operations in Ukraine offered Moscow a similar opportunity to use these new systems in combat.

The conflict in Syria allows Russia an opportunity to learn how cutting-edge U.S. systems respond to electronic attacks.

Gen. Raymond Thomas, the head of U.S. Special Operations Command, said this year that Syria has become “the most aggressive [electronic warfare] environment on the planet.”

Speaking at a conference in Florida in April, Thomas said: “They are testing us every day,” knocking communications down and even disabling aircraft built for electronic warfare.