Yes, about 10,000 or so ISIS militants have been killed in Iraq and Syria, the Department of Defense admits—though it hadn't planned to actually tell anyone that number. "The estimated of the number killed is correct but was not intended for release," a DoD spokesman tells NBC News, adding that this figure includes killings by other forces outside of the US-led coalition against the Islamic group. Why officials are now having to scramble to explain what this stat means: because while subbing for John Kerry at a Paris coalition meeting yesterday, US Deputy Secretary of State Antony Blinken strayed off the usual MO during an interview with the France Inter radio station. "We recorded an enormous loss for [ISIS]. More than 10,000 since this campaign started. And this will eventually have an effect," he said, per CNN.
The problem is that a) this estimate was classified, and b) body count isn't used as a gauge of success for a few reasons, per NBC, which points out the "frequent and futile use" of body counts "in the Vietnam War was among the conflict's many lessons." Most notably, it's hard to ensure the numbers are accurate. The military hasn't spelled out its process, but experts believe body counts are culled based on satellite images, ISIS claims, and on-the-ground reports. Notable military leaders have also said in the past that body counts don't take into account war's nuances, such as morale and how commanders can get caught up in a "numbers game that compromises their integrity," per a 1991 Los Angeles Times article—underscoring the longtime tradition of not citing these figures.