The top U.S. commander in the Middle East has a message for troops: stop posting videos of missile strikes on social media, because Iran is watching — and using that footage to make its next attacks deadlier.

According to a Reuters report on Wednesday, Adm. Brad Cooper, head of U.S. Central Command (CENTCOM), told troops in a July 28 letter to "redouble our focus on operational security." He said Iran can search reports and posts containing "reactions, photos, and footage from the cellphones of our troops" to learn whether missiles and drones hit their targets.

"The direct, unavoidable cost of this open-source intelligence could be measured in the lives of American service members and civilian residents in targeted Gulf countries," Cooper wrote.

The conflict, which began Feb. 28, has killed 18 U.S. troops and wounded more than 600. Iran has targeted bases in Jordan and Gulf states, while fighting around the Strait of Hormuz has disrupted shipping and energy markets.

Cooper's letter cited a specific example: footage recorded on Meta smart glasses during a July 17 Iranian attack on Muwaffaq Salti Air Base in Jordan. The Instagram video showed a service member running and entering a bunker.

"Iran knows the weapons were fired; however, their forces do not know if they missed by 50 meters, hit an empty tarmac, or successfully struck a crowded facility," Cooper wrote. He said public accounts were "essentially performing Iran's Battle Damage Assessment for them, free of charge." Such disclosures, he added, could become "an immediate green light" for Iran to launch a "secondary, much more devastating wave of attacks."

This isn't a new concern for the Pentagon. A 2018 Defense Department policy prohibited geolocation features on government and personal devices in operational areas after fitness trackers and other applications exposed location data. The military has long treated personal electronics as battlefield vulnerabilities.

Now, some troops in Jordan have been told commanders could confiscate their phones, according to Reuters. CENTCOM spokesperson Capt. Timothy Hawkins called Cooper's letter "a general reminder" about operational security, not confirmation of a regionwide policy.

MarketDash reached out to CENTCOM for additional details on Cooper's letter but did not receive an immediate response.