“The Middle East is on a knife’s edge and a broader escalation can imperil both Israeli and US interests,” he said during a virtual event hosted by the Carnegie Endowment for International Peace.

Iran fired a salvo of ballistic missiles at Israel on Tuesday in retaliation for Israel’s campaign against Tehran’s Hezbollah allies in Lebanon. Alarms sounded across Israel and explosions could be heard in Jerusalem and the Jordan River valley after Israelis piled into bomb shelters.

Iran has vowed to retaliate following attacks that killed the top leadership of its Hezbollah allies in Lebanon.

The firing of missiles came after Israel said its troops had launched ground raids into Lebanon, though it described the forays as limited. The Israeli campaign in Lebanon is the biggest escalation of regional warfare since fighting erupted in Gaza a year ago.

Campbell described Iran’s actions as “deeply irresponsible” and stressed the necessity of a coordinated “return message” to Tehran.

“We acknowledge that while a response is essential, the region is on a knife’s edge, raising serious concerns about broader escalation,” Campbell stated. He warned that sustained hostility could jeopardise not only Israel but also US strategic interests.

While commenting on the recent attacks from Lebanon into Israel, he labelled them as “destabilising” and cautioned against prolonged conflict with Lebanon.

“We support some of Israel’s actions, but we are wary of extended ground operations in Lebanon,” Campbell added and highlighted the delicate balance the US seeks to maintain in the region.

When asked about the US reaction to the Iranian attacks, he said that consultation and coordination with Israel was to keep lines of communication open and to make sure those perspectives are understood.

He concluded his response, “The amount of time and focus that this is taking from our senior leadership cannot be underestimated.”