The Pentagon is still shaking, after the rhetorical bomb Secretary of Defense Ashton Carter dropped on the place yesterday.

The new Secretary of Defense blasted military officials for telling reporters that Iraqi and U.S.-led coalition forces could launch an offensive to reclaim a major Iraqi city as early as April. He called their statements inaccurate and a “mistake.”

“That clearly was neither accurate information nor, had it been accurate, would have been information that should be blurted out to the press,” Carter told the Senate Armed Services Committee on Tuesday about suggestions that the campaign to reclaim the city of Mosul could begin in spring. “So it’s wrong on both scores.”

Carter’s not off-base; the briefing was overly optimistic, maybe even foolhardy. But Carter did not give a full accounting of the facts, either. The briefing he criticized wasn’t a one-time slip-up; U.S. officials had been suggesting a spring attack on Mosul for months. Moreover, the Pentagon-sanctioned official who briefed reporters left open the possibility of moving that timeline “to the right” if the Iraqis were not ready. In other words, the April-May timeline was hardly set in stone.

Yet Carter accused the briefers of revealing “military secrets.” There was nothing even remotely classified in the presentation.

Regardless, Carter’s public admonition, along with his repeated assertions that the Pentagon must protect the civilian-led chain of command, has had a chilling effect on those in uniform who said they have heard one message from the newly-minted Defense Secretary.

“Don’t talk to the media,” one defense official told the Daily Beast.

The Defense Department hasn’t exactly been press-friendly of late, especially when it comes to the war against ISIS. Unlike earlier conflicts, few reporters have been allowed to embed with U.S. troops, even those training Iraqi forces on well-secured bases. Basic statistics about the American-led air campaign have had to be pried free from the Pentagon—even though the effort has cost the U.S. at least $1.5 billion and hit more than 2,500 targets. By the way: The Defense Department hasn’t admitting to killing a single civilian in those 2,500+ attacks.

On February 19, Pentagon officials scheduled a 30-minute briefing with reporters to update the public on the U.S.-led campaign against the self-proclaimed Islamic State. The briefing conditions were that the briefer could only be identified as a CENTCOM official. Among the topics: the potential military campaign to retake Mosul, Iraq’s second-largest city, considered a keystone of the U.S.-led effort to rid Iraq of the Islamic State. Mosul is ISIS’s capital in Iraq and the largest city it controls.

That official said a Mosul offensive could begin in April or May, taking as many as 25,000 troops, and spelled out where some of the units would come from. Some of those forces were still receiving training, the official said, but would not say with any specificity how the U.S. would use its airpower to support such a campaign.

The official said the troops would confront as many as 2,000 ISIS fighters. And he stressed that such a timeline would “move to the right,” likely to fall, if the Iraqis were not ready.

The briefing caused an immediate uproar in both Iraq and Washington, with some blasting the Pentagon for telegraphing its proposed war plan. In a letter to President Barack Obama, Senators Lindsey Graham and John McCain called the decision to share such details.

“These disclosures not only risk the success of our mission, but could also cost the lives of U.S., Iraqi, and coalition forces,” Graham and McCain wrote in that letter.

More importantly, many inside the Pentagon felt the timeline was overly optimistic as The Daily Beast first reported, given the Iraqi forces’ readiness and concerns from the Iraqi government about conducting such an operation so soon. The public uproar caused some to declare that an offensive was more likely in fall.

But as it turned out, the CENTCOM official offered few new details. Talk of a spring offensive to reclaim the city appears to have first happened publicly on December 10, when Brett McGurk, the State Department’s special presidential envoy for defeating the militant group, testified before the House Foreign Affairs Committee that such a timeline was possible. Moreover, he said it would be “reasonable” to estimate such an offensive would take as many as 25,000 Iraqi troops.

The military endorsed that timeline a month later. In January, U.S. Central Command chief Gen. Lloyd Austin gave an interview to The Wall Street Journal, saying it could happen in the spring or summer. Austin stressed that Iraq, led by two divisions, would conduct the ground offensive.

“If we did things alone or with some of the other allies on the ground, it could move faster,” Austin said in that interview. “But the Iraqis have to do this themselves.”

In at least three instances afterward, Navy Rear Admiral John Kirby, the Pentagon’s chief spokesman, talked about a potential Mosul campaign, but hesitated to commit to a potential spring timeline.

But the decision to spell out all the details in one briefing led many to interpret the CENTCOM official’s comments as an effort to telegraph the campaign. On Tuesday, appearing before the Senate Armed Services Committee, Carter was asked again about the briefing, prompting his answer.

“Every once in a while, somebody gets out in front of their skis,” he added.

Carter’s comments come after his decision to replace Kirby as spokesman within a day of taking office, even with no one lined up to replace him. Many assume he will replace Kirby with a civilian, and Carter has said he will be more available to reporters.

The decision to publicly criticize an official who spoke accurately about the war raises fears among some that an already opaque war will become more so as those in uniform fear speaking up.

On Tuesday, for example, Austin told lawmakers that the coalition had killed 8,500 ISIS fighters since August, when the campaign began. That is 2,500 people higher than the last estimate provided by U.S. officials just 40 days ago.

On January 22, Stuart Jones, the U.S. ambassador to Iraq, told Al Arabiya that “we estimate that the airstrikes have now killed more than 6,000 ISIS fighters in Syria and Iraq.”

That is, on average the U.S. claims to have killed between 37.5 and 62.5 ISIS fighters a day, depending on whether the U.S.-led coalition killed 6,000 and 6,999 ISIS fighters.

But no one would say how the U.S. tallied that estimate, where those deaths occurred, or which coalition member strikes contributed to that figure. Rather, officials called the figures an estimate based on battlefield assessments. Any further details were classified, they added. And they continue to insist there are no confirmed civilian casualties among those killed.

Carter’s comments only made officials more reticent to defend those numbers.

“I will defer to Austin’s comments,” three officials told The Daily Beast on Tuesday when clarity on the general’s assertion was sought.