There have been at least 40 attacks against U.S. and coalition troops in Iraq and Syria in recent weeks, carried out by Iranian-backed forces. The U.S. has hinted that its airstrikes against Tehran-linked groups in Iraq and Syria would continue if they continued to attack American targets.

"It's a tough balancing act," says Vice Adm. Robert Murrett (Ret.), professor of practice of public administration and international affairs. "The big issue is responding to attacks that are being done by Iranian surrogates in a measured way that has a deterrent effect but does not cause the tension that exists in the area in the conflict to expand to the next level."

He says it not just down to whether Iran's surrogates launch more attacks on U.S. targets but also what action the Tehran-backed Hezbollah group in Lebanon may take against northern Israel.

"We will have to look at it day-to-day," he says. "I think the United States and the Iranians understand each other very clearly. We disagree about a lot of stuff, but I think the signals and the activity that we're taking on the military front will hopefully have a deterrent effect and keep the conflict from widening."

Read more in the Newsweek article, "US in 'Tough Balancing Act' to Hit Iran Targets Without Expanding Gaza War."