We know that a U.S. strike on Syria would likely involve involve bombs or cruise missiles. But if the president orders an attack against the regime of President Bashar al-Assad, it will likely include another instrument as well: cyberattacks.
Experts say President Obama is unlikely to order the kind of stand-alone cyberattack against Syria that the United States launched against Iran's nuclear facilities a few years ago. But digital sabotage could play a significant role in an American military strike if Congress approves an intervention.
Syria's air defenses would likely be among the first targets of any cyberattack, the experts said. U.S. forces could trick the country's radar system into seeing nothing as American jets passed overhead, or disrupt Syrian missile sites designed to shoot down U.S. aircraft. American engineers also could disable Syria's power grid remotely while the intervention was ongoing, then bring the system back online. They might take down Syrian command-and-control networks, or, in a move reminiscent of more traditional electronic warfare, jam the Syrian army's communications or block its propaganda.
Any cyberattack would be relatively difficult to detect, said James Lewis, a cybersecurity scholar at the Center for Strategic and International Studies.
"We might not see anything at all," he said. "It probably wouldn't look like anything until it was all over. The best attacks would be ones where the Syrians never noticed they were being interfered with."
Exactly what the Pentagon's network exploitation would look like depends on a number of factors including the scale of the conventional assault, who gets assigned to carry out the digital attack and calculations about the wider political consequences of using cyberattacks in a military fashion (as opposed to cyberespionage).
The hope for a limited engagement might lead Obama to narrow his target list down to the specific unit that carried out the chemical weapons attacks, suggested Peter W. Singer, a senior fellow at the Brookings Institution. Such a decision might demand different tools — aircraft over cruise missiles, for example — that could affect the nature of the supporting cyber operation.
If Obama commits to using digital force, it'll be up to the Pentagon to decide which of its hackers performs the job. While the NSA has one of the most robust network exploitation teams on earth, the U.S. Air Force also has its own cyber capabilities and would be well-equipped to disrupt Syria's air defenses. If the objectives expand to include more than air defenses, said Lewis, the Navy or U.S. Cyber Command could become involved.
Many of these same questions arose during the Obama administration's intervention in Libya. However, most observers agreed that there wasn't enough time for U.S. hackers to gain entry to Libyan systems, making a successful cyberattack more difficult.
Obama has had ample time to prepare for a Syrian intervention. But the president might still decide that using cyberattacks this time is too risky. Not only would it set an important precedent and raise difficult legal questions — what happens if, in order to reach a target in a combatant country your hackers have to go through a neutral country's servers? — but it could potentially give away crucial tactical secrets. Disabling Russian-made surface-to-air missiles in Syria, for example, would signal to Moscow that the United States had the know-how to do it.
"Why would we show that we have the capability to take down SA-3s and SA-5s?" said Jason Healey, a cybersecurity scholar at the Atlantic Council. "If you have a Ferrari, you only take it out on race day."
It might be better to save that capability for a more strategic opportunity, the experts said. But, Healey said, there may be an important humanitarian argument for using cyberattacks as part of a Syria intervention. And that could establish a positive international precedent, too.
By disabling a power plant for several hours instead of bombing it, the White House could spare Syria much of the civilian and economic toll of a more traditional attack. If the power needs to be cut either way, using a cyberattack could achieve the same goal with minimal collateral damage.
"If we say the laws of war apply to cyberspace, here is an opportunity to demonstrate that," said Healey. "If we turn out the lights in Damascus by blowing them up, that would be completely legitimate, completely in line with the Geneva Conventions. And yet because we are a humanitarian military and we are concerned about civilian impact, we could say we felt compelled to use cyberweapons because it was more in line with the Geneva Conventions.
"I would be shocked if we made that case," Healey added.