A U.S. show of force appears to have been enough to get Iran to back down, after Tehran’s naval forces repeatedly targeted ships in and around the Strait of Hormuz and the Gulf of Oman earlier this year.
The commander of U.S. Air Forces Central Command said Wednesday that the decision in July to send F-35 and F-16 fighter jets to the Persian Gulf, along with a naval destroyer and an amphibious assault group that included 2,500 U.S. Marines, seems to have resonated with Iranian officials.
"The increased presence of surface vessels that went in ... combined with our airpower has deterred Iran from taking any actions against maritime shipping," Lieutenant General Alexus Grynkewich told members of the Defense Writers Group in Washington.
“It has had good effects,” he added.
U.S. Defense Secretary Lloyd Austin ordered the additional U.S. capabilities to the region after Iran attempted to seize two commercial tankers in international waters off the coast of Oman in early July, which followed Iran’s successful seizure of two oil tankers transiting the Strait of Hormuz just months earlier.
The U.S. Navy says, in all, Iran has seized or harassed almost 20 ships in the region over the past two years.
In contrast, reports from Iran’s state-run media on some of the ship seizures have said Iran’s actions have been part of efforts to combat illegal fuel smuggling, and they have claimed that at least some of the vessels were in Iran’s territorial waters.
Still, Grynkewich cautioned Wednesday that Washington’s ability to deter Iran from meddling with commercial shipping might be short-lived, especially since the increased U.S. presence is only temporary and some of the forces are slated to head back home.
“I don't know, if they see a change in [U.S.] posture, how they will react,” he said.
The top Air Force general in the Middle East also suggested Tehran’s decision to hold back may be part of a larger political calculation.
"It doesn't suit their political ends right now to resort to violence," he told reporters. “Part of that is an Iranian assessment that that would go contrary to kind of their diplomatic outreach initiatives that are ongoing, trying to portray themselves as a responsible partner.
“But there's no doubt in my military mind, at least, that they would resort to that at some point in the future if they saw it as in their interests."
Of particular concern to the United States and its allies in the region is Iran’s growing network of militias and proxy forces, spanning Iraq, Syria and Lebanon, which officials say continue to grow in strength and in influence with support from Tehran.
U.S. officials say those groups have been stockpiling Iranian-made weaponry, including drones, short-range missiles and an assortment of small arms, for three to four months.
Additionally, they see indications that members of the Quds Force within Iran's Islamic Revolutionary Guard Corps have been helping to train, advise and assist the militias and proxy forces so they are better prepared if Iran decides to act.
There are also signs that Iranian forces may be getting antsy.
Late last month, the U.S. Navy accused Iranian sailors of repeatedly shining a laser at a U.S. helicopter flying through international airspace over the Persian Gulf.
And in August, U.S. counterterrorism officials warned that intelligence suggested Iran’s own intelligence and security services “are advancing plotting against the United States, other Western interests and Iranian dissidents more aggressively than they have at any time since the 1980s."
Should Iran decide to again ramp up harassment of commercial ships, however, Air Force Central Command’s Grynkewich said U.S. forces would be ready with another show of force.
“The United States is absolutely willing to come back in and surge forces one more time," he said.