In a letter, Admiral Brad Cooper said Iran was monitoring such videos in near real time to gauge whether its strikes had 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 to the troops in letter dated July 28. Cooper’s warning comes as the military seeks to restrict information that could help Iran inflict more casualties on US forces. It follows the deaths of four US troops in recent weeks, after fighting with Iran resumed with the collapse of Trump’s ceasefire. Eighteen US troops have been killed and more than 600 wounded since the conflict with Iran began in February.