WASHINGTON — The Obama administration has been eager to show momentum against the Islamic State after a conference last week dramatized the hurdles to countering the terrorist group’s propaganda. But the Pentagon may have gone too far in sharing its military planning.
On Thursday, a senior official from the American military’s Central Command told reporters that Iraqi and Kurdish forces, with help from the United States, were preparing to launch an assault to retake the Iraqi city of Mosul in April or May, before the searing heat of the Iraqi summer. The assault force, the official said, would consist of up to 25,000 Iraqi and Kurdish troops.
The unusual level of detail about timing and the size of the force ignited a furor on Capitol Hill, where Senator John McCain, the Arizona Republican who is chairman of the Armed Services Committee, and Senator Lindsey Graham, a South Carolina Republican, sent an angry letter to President Obama. They wrote that the disclosures “not only risk the success of our mission, but could also cost the lives of U.S., Iraqi, and coalition forces.”
Mr. McCain and Mr. Graham demanded to know whether the White House had authorized the disclosures and said the officials responsible must be held accountable. The White House responded that it had no involvement in the briefing, noting in a statement by a spokeswoman for the National Security Council, Bernadette Meehan, that “the U.S. military makes a judgment about what information is shared regarding their operations.”
The disclosures also caught the new defense secretary, Ashton B. Carter, by surprise. “The secretary is always concerned about operational security and wants us to be mindful that we don’t put information out there that isn’t necessary,” a senior defense official told reporters traveling with Mr. Carter on Friday to Afghanistan, his first overseas trip in his first week on the job.
Mr. Carter pointedly declined to tell reporters on his plane when the operation to retake Mosul might begin. “It’s important that it be launched at a time when it can succeed,” Mr. Carter said.
The Pentagon press secretary, Rear Adm. John F. Kirby, said on Saturday that the department would “respond appropriately to the senators’ concerns and in an expeditious manner.”
Despite all the second-guessing, it was not clear how useful or startling the disclosures will be to Islamic State fighters. For months, administration officials have telegraphed that the assault on Mosul would come in the spring, a timetable dictated by the summer heat and the religious calendar: Ramadan begins on June 17.
The disclosure that up to 25,000 troops will take part — five Iraqi brigades and three brigades of Kurdish pesh merga fighters — was noteworthy. But the size of the Iraqi military, and the number of brigades it could afford to devote to the Mosul operation, is not a mystery.
The Central Command official, who spoke on the condition that he not be identified by name, did not provide details on tactics or geographic coordinates. Nor did he answer perhaps the most sensitive question: whether the United States plans to deploy ground troops as air controllers, helping the Iraqis call in airstrikes on Islamic State positions.
That politically sensitive decision will be made by Mr. Obama, based on a recommendation by the chairman of the Joint Chiefs of Staff, Gen. Martin E. Dempsey. General Dempsey has said he may recommend ground troops if he determines they are needed.
Senior Pentagon officials pushed for the Central Command briefing largely to demonstrate the steps the military was taking to counter the Islamic State’s propaganda campaign. It came at the end of a three-day White House conference on combating violent extremism, which showcased the uphill nature of the challenge for the West.
Although the disclosures surprised some of the reporters who took part in the briefing, a senior defense official insisted they were not out of the ordinary: the Pentagon’s top commanders who direct operations overseas have considerable leeway in what they choose to disclose. Central Command, or Centcom, which is responsible for military operations in the Middle East, is based in Tampa, Fla.
“We want Centcom to provide briefings,” the official said. “And we welcomed this one.”