The Senate Intelligence Committee says the attack on a U.S. diplomatic post in Benghazi on September 11, 2012 was preventable, but the State Department says there was "no specific threat." (Reuters)

The Senate Intelligence Committee says the attack on a U.S. diplomatic post in Benghazi on September 11, 2012 was preventable, but the State Department says there was "no specific threat." (Reuters)

A long-delayed Senate Intelligence Committee report released Wednesday faulted both the State Department and the intelligence community for not preventing attacks on two outposts in Benghazi, Libya, that killed four Americans, including the U.S. ambassador, in 2012.

The bipartisan report laid out more than a dozen findings regarding the assaults on a diplomatic compound and a CIA annex in the city. It said the State Department failed to increase security at its mission despite warnings, and blamed intelligence agencies for not sharing information about the existence of the CIA outpost with the U.S. military.

The committee determined that the U.S. military command in Africa didn’t know about the CIA annex and that the Pentagon didn’t have the resources in place to defend the State Department compound in an emergency.

“The attacks were preventable, based on extensive intelligence reporting on the terrorist activity in Libya — to include prior threats and attacks against Western targets — and given the known security shortfalls at the U.S. Mission,” the panel said in a statement.

The report also noted, chillingly, that the FBI’s investigation of the attacks has been hampered in Libya and that 15 people “supporting the investigation or otherwise helpful to the United States” have since been killed in Benghazi. The report said it was unclear whether those killings were related to the inquiry.

Read the report A bipartisan report lays out more than a dozen findings rgarding the 2012 assault on the diplomatic compound in the Libyan city of Benghazi. Read it.

The report found no evidence of the kind of political coverup that Republicans have long alleged. Much of it recounted now-familiar facts about deteriorating security conditions in Benghazi in 2012, a year after the fall of longtime dictator Moammar Gaddafi. It filled in new details about the relationship between the State Department compound and the CIA annex about a mile away, and described the concern among many intelligence specialists about the growing potency of Islamist militants in the city.

“In spite of the deteriorating security situation in Benghazi and ample strategic warnings, the United States government simply did not do enough to prevent these attacks and ensure the safety of those serving in Benghazi,” said Sen. Saxby Chambliss (Ga.), the ranking Republican on the panel.

In response to the report, the State Department issued an update of its efforts to improve security at overseas posts and make other changes recommended by an independent oversight panel — the Accountability Review Board — shortly after the attacks.

“While risk can never be completely eliminated from our diplomatic and development duties,” the State Department statement said, “we must always work to minimize it.”

The agency said it is refining procedures for assessing risk and evaluating security measures in highly volatile areas, including when to depart from the usual reliance on locally hired security guards. “Hard decisions must be made when it comes to whether the United States should operate in dangerous overseas locations,” the statement said.

State Department deputy spokeswoman Marie Harf said the Senate report adds little new information and does not do much to expand the government’s understanding of the attacks. “We should have been better then, and we need to get better going forward,” she said.

The report was based on dozens of committee hearings, briefings and interviews — including with survivors of the attacks, which occurred in September — and on thousands of pages of intelligence and State Department materials collected between September 2012 and December 2013.

The document contains only one mention of then-Secretary of State Hillary Rodham Clinton, whom the panel’s Republicans name as the official who should ultimately be held responsible for the failures in Benghazi. Even so, the report is likely to provide fodder for both Republicans and Democrats as Clinton ponders a possible presidential run in 2016.

The committee described the attacks as opportunistic and said there was no specific warning that they were about to be carried out.

The report said that on Sept. 18, 2012, the “FBI and CIA reviewed the closed circuit television video from the Mission facility that showed there were no protests prior to the attacks.”

But it took six more days for intelligence officials to revise their chronology of events and say that “there were no demonstrations or protests” at the diplomatic compound “prior to the attacks.”

The report said it was problematic that the CIA and State Department were not working out of the same facility in the dangerous environment. That meant the CIA and its well-trained contractors, who had served in elite U.S. forces, were not at the compound in the event of a crisis.

Six armed CIA employees and a linguist responded to the attack on the compound late on Sept. 11, the report says. About 30 minutes passed before the CIA team arrived and “exchanged fire with the attackers.” They neither asked permission to aid those inside nor were told to stand down.

Detailed accounts provided to the committee describe a harrowing assault and U.S. personnel scrambling to survive it.

Attackers used “diesel fuel to set the main building ablaze, and thick smoke rapidly filled the entire structure,” the report says. According to testimony by the director of the National Counterterrorism Center, a diplomatic security agent led U.S. Ambassador J. Christopher Stevens to an escape window at the compound.

“Nearing unconsciousness himself, the agent opened the emergency escape window and crawled out. He then realized he had become separated from the Ambassador . . . so he reentered and searched the building multiple times,” the report says. “The DS agent, suffering from severe smoke inhalation, climbed a ladder to the roof where he radioed the other DS agents for assistance and attempted unsuccessfully to ventilate the building by breaking a skylight.”

Stevens and another U.S. diplomat were killed.

The committee found that the military response to the attacks was slow and hindered, but not purposely so. “At approximately 1:15 a.m. Benghazi time [on Sept. 12], a seven-man reinforcement team of additional U.S. security personnel from Tripoli landed at the Benghazi airport and began to negotiate with the local Libyan militias for transportation and a security convoy,” the report says. The team did not leave the airport for more than three hours.

A separate attack on the CIA annex about 5:15 a.m. on Sept. 12 resulted in the deaths of two security officers, who were killed by mortar fire “as they engaged the enemy from the roof of the Annex,” the report says.

In the weeks leading up to the attacks, the CIA knew that conditions on the ground were worsening. In August, the agency alerted the intelligence community to Islamist training camps and militias in Benghazi. The agency said it was concerned about local militias providing security at U.S. facilities and about the outpost’s lack of defense.

That same month, 20 security incidents occurred in Benghazi.

The report said that the Libyan militia charged with protecting the diplomatic compound didn’t defend it during the attack.

Republicans on the committee accused the White House of obstructing the report, which the panel had wanted to complete much earlier, and said that Patrick F. Kennedy, the U.S. undersecretary of state for management, shielded the Obama administration from congressional oversight.

Sen. Susan Collins (R-Maine) said Kennedy “failed to ensure that a facility he personally approved in December 2011 had the necessary security to match the heightened threat environment.”

The FBI has charged 13 people in connection with the attacks in sealed criminal complaints. More charges are expected. Members of the terrorist group Ansar al-Sharia, based in the Libyan city of Darnah, have been implicated. The report says that “key information gaps remain about the potential foreknowledge and complicity of Libyan militia groups and security forces, the level of pre-planning for the attacks, the perpetrators and their involvement in other terrorist activities and the motivation for the attacks.”

A former detainee at Guantanamo Bay, Cuba, named Abu Sufian bin Qumu runs Ansar al-Sharia. Qumu is mentioned in one of the report’s footnotes, but the context was redacted in the version that was publicly released.

Aaron Blake contributed to this report.