WASHINGTON -- Defense Secretary Leon E. Panetta said Thursday that he and top military commanders "felt very strongly" that deploying American forces to defend against the fatal attack last month on the United States diplomatic compound in Benghazi, Libya, was too risky because they did not have a clear picture of what was happening on the ground.
"There's a lot of Monday-morning quarterbacking going on here," Mr. Panetta told reporters at the Pentagon, adding that "the basic principle is that you don't deploy forces into harm's way without knowing what's going on, without having some real-time information about what's taking place."
As a result, Mr. Panetta said, he and two top commanders "felt very strongly that we could not put forces at risk in that situation." The commanders are Gen. Martin E. Dempsey, the chairman of the Joint Chiefs of Staff, and Gen. Carter F. Ham of Africa Command, which oversees American military operations in Africa, including Libya.
Mr. Panetta was at the White House for a regular meeting on the afternoon of Sept. 11 as the first reports of the attack unfolded, an American official said. By that evening Mr. Panetta had consulted with General Dempsey and General Ham and had ordered a number of American military forces in the region to move closer to Libya.
Defense officials say they did not receive a request for military support from the State Department as the attack unfolded.
In response to Mr. Panetta's decision, a small Special Operations "strike force" team moved from Central Europe to the Sigonella Air Base in Sicily while two Navy destroyers already in the Mediterranean were moved off the Libyan coast. A rapid-reaction team of elite Marines left Rota, Spain, and arrived to protect the American Embassy in Tripoli, the Libyan capital, the next day.
But a senior military official said that uncertainty about what was happening on the ground in Libya delayed the decision about where to send the Special Operations forces until about 9 p.m. in Washington, or 3 a.m. on Sept. 12, in Libya.
Ultimately, the decision relayed from the military's Joint Staff in Washington was "to get close but not into Libya," the official said. The task force then deployed over the next 24 hours to Sigonella, which is about an hour by plane from Benghazi. But by that time the shooting was over and the Americans were eventually evacuated.
As Mr. Panetta told reporters on Thursday, "This happened within a few hours, and it was really over before we had the opportunity to really know what was happening."
Republicans, in the meantime, continue to question the Obama administration about its handling of an event that has become a source of sharp debate in the presidential campaign.
On Thursday, Speaker John A. Boehner of Ohio released a letter asking the president to answer a number of questions about Libya publicly, including what military options he had been offered or had considered during the attack and its immediate aftermath.
Mr. Boehner also said in his letter that "information now in the public domain contradicts how you and senior administration officials consistently described the cause and nature of the terrorist attack in the day and weeks immediately following."
Why, Mr. Boehner asked, "did the administration fail to account for facts that were known at the time?"
Mr. Boehner sent his letter after a series of three leaked e-mails sent by State Department officials shortly after the attack began -- including one that alerted the White House Situation Room that a militant group had claimed responsibility for it -- stirred new debate on Wednesday about the Obama administration's shifting accounts.
The first e-mail, sent about a half-hour after the assault began, said the State Department's regional security officer in Tripoli had reported that the mission in Benghazi was under attack, and that "20 armed people fired shots." A second said the firing at the mission had stopped. In the third, the embassy in Tripoli reported that a local militant group, Ansar al-Shariah, had claimed responsibility through postings on Facebook and Twitter.
Eric Schmitt contributed reporting.
This article originally appeared in The New York Times.