The U.S. retaliatory strikes against Iranian targets in Syria and Iraq will only succeed if they convince Iran to stop pushing its proxies to attack American personnel and installations "anywhere in the world," according to former officials.
"The single measure of their effectiveness will be whether they deter further Iranian aggression," Mike Pompeo, secretary of state during the Trump administration, told Fox News Digital.
"Not just aggression in Jordan or Iraq, but Iranian attacks on U.S. interests anywhere in the world, support for Hamas and Hezbollah against our ally Israel and Iranian attacks on military and commercial vessels in the Red Sea included," he explained.
He stressed he is not certain of the effect since he does not know the exact targets hit by the U.S.
US RETALIATORY STRIKES WILL PROVE ‘INEFFECTIVE’: KIRK LIPPOLD
"To achieve this, after such a delayed response following the killing of three Americans, will take a level of seriousness and willingness to impose real costs on Iran we have not seen to date," he added. "This failure has caused escalation that will not stop until the Biden administration — along with our allies — restores deterrence."
Two U.S. defense officials confirmed to Fox News chief national security correspondent Jennifer Griffin the U.S. commenced strikes against targets tied to Iran’s Islamic Revolutionary Guard Corps (IRGC) and affiliated militia groups in Syria and Iraq.
The strikes started at around 4 p.m. EST Friday, hitting 85 targets across six locations, including command and control headquarters, weapons storage facilities, underground bunkers and more hardened targets than in the past.
President Biden authorized the strikes in response to the deaths of three U.S. service members Sunday during a strike in Jordan that also injured 40 other service members. The Iraqi group Kata’ib Hezbollah committed to halting military operations under pressure from the Iraqi government and the group’s backers in Iran.
U.S. Secretary of Defense Gen. Lloyd Austin confirmed the attacks an hour after their execution, specifically naming the IRGC and stressing that the U.S. does not "seek conflict in the Middle East or anywhere else," but the Biden administration "will not tolerate attacks on American forces."
"We will take all necessary actions to defend the United States, our forces and our interests," Austin promised.
Former military officials provided cautious reactions to news the U.S. carried out the much-anticipated strikes, with at least one former rear admiral suggesting the long delay allowed proxy groups to shift personnel away from potential targets.
"This is a long overdue strike," retired Rear Admiral Mark Montgomery, a senior fellow at the Foundation for Defense of Democracies, told Fox News Digital.
"I suspect that the delay in timing will mean most IRGC forces will have packed up their bags and returned to Iran," Montgomery suggested. "Even the proxy force numbers may be low. This is a good target package for day one. I hope it is part of a sustained campaign over weeks.
"It’s also good to see long-range bombers utilized as they can employ more cost-effective ordinance options," he added, saying the strikes can "only restore deterrence if they are sustained and persistent."
Former CENTCOM Cmdr. Joseph Votel during an appearance on "Your World with Neil Cavuto" called the widespread strikes "unsurprising" and argued that pursuing "dozens and dozens" of targets simultaneously is "well within our capabilities."
"The strikes in Syria indicate to me that we are trying to go after, certainly the militia groups that are operating from that area that may have been responsible for this, plus, perhaps, some of the Iranian advisers and leaders and facilities that were supportive of that," Votel explained.
"So, I think we're going to have … to wait a little bit," he continued. "We have to be patient to kind of see what, what the plan is as it unfolds in the coming hours and in coming days.
"Certainly, they recognize they crossed the red line here with the death of our soldiers, so there certainly has been a reaction on the ground by militants," Votel added.
He noted it remains unclear if the buildings hit have enough value compared to striking against leaders and "others who are actually responsible for making the decisions" for these attacks.
"This first tier might be after the militant groups, and the next tier might be after those that are enabling those, those militant groups," Votel suggested.
Fox News' Jennifer Griffin and Fox News Digital's Brie Stimson and Sarah Rumpf-Witten contributed to this report.
