Lax security and poor communication contributed to a deadly assault on an American diplomatic compound in Benghazi, Libya, according to a new report by the State Department.

The Benghazi attack, which killed four Americans -- among them a well-respected ambassador -- has been a source of intense controversy for the Obama administration. Officials have faced allegations of having downplayed the role of terrorist elements in the attack, a criticism that led U.N envoy Susan Rice to withdraw herself from the running to be secretary of state.

While the newly released report does not draw any conclusions about the motivations or allegiances of the assailants, it faults a lack of security for allowing the attackers to succeed.

“Systemic failures and leadership and management deficiencies at senior levels within two bureaus of the State Department (the ‘Department’) resulted in a Special Mission security posture that was inadequate for Benghazi and grossly inadequate to deal with the attack that took place,” the report says.

The Benghazi mission’s temporary status was partially to blame, resulting in a staff without deep knowledge of the region and a lack of coordination with other branches of the State Department.

“Communication, cooperation, and coordination between Washington, Tripoli, and Benghazi occurred collegially at the working-level but were constrained by a lack of transparency, responsiveness, and leadership at senior bureau levels,” the report reads.

But the report also found that Benghazi and the main Libya mission in Tripoli were denied requests for resources, illustrating a situation in which diplomats are also not given the tools they need because of a mindset “conditioning a few State Department managers to favor restricting the use of resources as a general orientation.”

“Congress must do its part to meet this challenge and provide necessary resources to the State Department to address security risks and meet mission imperatives,” the report said.

Part of the problem, the report notes, is that diplomats dispatched abroad face “significantly increased be present in the world’s most dangerous places,” where they must strike a balance between protecting themselves and venturing out into the countries they have been sent to serve in.

“This growing, diffuse range of terrorist and hostile actors poses an additional challenge to American security officers, diplomats, development professionals and decision-makers seeking to mitigate risk and remain active in high threat environments without resorting to an unacceptable total fortress and stay-at-home approach to U.S. diplomacy,” the report says.

The report also includes a detailed chronology of the attack, helping to clarify a timeline that was in dispute in the early days of the administration’s response to what at first seemed to be a spontaneous response to a popular protest.