As the battle for Mosul approaches, an electronic war is already raging

A coalition of Kurdish and Iraqi fighters, backed by the United States, is preparing to retake Mosul, Iraq, one of two de facto headquarters of the Islamic State (IS), Defense Department leaders announced in a press conference this week. But as ground forces make final preparations, the electronic war against IS is already beginning.

US forces are spying on and disrupting IS’s radio and online communications in Mosul, Defense Secretary Ash Carter announced on Monday. The cyber attacks, he said, will “disrupt [IS's] command and control, to cause them to lose confidence in their networks, to overload their network so that they can't function, and ... interrupt their ability to command and control forces there.”

Electronic attacks have been part of American military operations since the Gulf War in 1991, when US forces used radio-frequency jammers to disrupt Iraqi communications. Jammers also allowed US soldiers to disable remotely-detonated bombs during the Iraq War. This is the first time the Department of Defense has ever formally announced cyber attacks as part of a military operation.

Secretary Carter didn’t give details about the attacks, telling reporters, “We don't want the enemy to know when, where, and how we're conducting cyber operations. We don't want them to have information that will allow them to adapt over time.” But he did say that the operation is designed so that IS fighters won’t know whether communications outages are the result of cyber attacks or of garden-variety connection problems.

The cyber attacks could take the form of denial-of-service attacks to take IS servers offline and make it difficult for group members to communicate with one another and to distribute propaganda. US Cyber Command may also spy on networks to figure out the physical locations and activities of IS commanders, and may inject false information or erase real information to cause confusion and uncertainty in Mosul. These tactics may also be complemented by traditional radio-frequency jamming, which can disrupt cell phone and wireless Internet communications.

The cyber attacks are a way of virtually isolating IS, Carter said at the press conference. Before ground forces enter Mosul, he said, electronic warfare will “limit [IS’s] ability to conduct command and control, limit their ability to communicate with each other, limit their ability to conduct operations locally and tactically.”