A report obtained exclusively by Al Jazeera America's Investigative Unit reveals that the US State Department has known of inadequate security measures at American embassies and consulates for decades.
Even so, senior officials did not act to prevent attacks at some of the US most dangerous diplomatic posts, such as Benghazi in Libya.
The internal government report, by an independent panel of five security and intelligence experts, reveals that the September 11, 2012, attack on the US diplomatic post in Benghazi, Libya, exploited the State Department's failure to address serious security concerns at diplomatic facilities in high-risk areas.
The attack left Ambassador J Christopher Stevens and three other Americans dead and raised serious questions about safety and security at American embassies.
The panel concluded that the State Department's failure to identify worsening conditions in Libya and exemptions from security regulations at the US Special Mission contributed to the tragedy in Benghazi.
Lack of accountability
Patrick Kennedy, the under-secretary for management, approved using Benghazi as a temporary post despite its significant vulnerabilities, according to an internal State Department document included with the report.
In the report, the panel, chaired by Mark Sullivan, director of the US Secret Service, said the State Department's management of its security structure had led to blurred authority and a serious lack of accountability.
Left unaddressed, the control problem "could contribute to future security management failures, such as those that occurred in Benghazi", the report said.
The report also highlighted inadequate security training for diplomats, an absence of risk-management models and a "critical" need for intelligence analysts to be on the staff at the embassies.
Sullivan's panel noted that its findings and recommendations were not new to the State Department officials.
For the full investigation by Al Jazeera America, click here.