More than a month before a deadly drone strike that killed three U.S. soldiers in Jordan, U.S. Defense Secretary Lloyd Austin sought to reassure U.S. troops about the military’s ability to withstand attacks by Iran-backed militants.

Austin, in previously unpublished remarks to sailors aboard the Gerald R. Ford aircraft carrier on Dec. 20, said the number one reason the militants had failed to that point was that “they’re not very good at what they do.”

“Every day, Iranian proxies are shooting at our troops that are in Iraq and Syria. They haven’t been effective at all because (of) two reasons: Number one, they’re not very good at what they do,” Austin told the crew.