The attack has become a major issue in the presidential campaign, featuring prominently in Republican candidate Mitt Romney's latest foreign policy address on Monday. He called it an example of President Barack Obama's weakness in foreign policy matters, noting: "As the administration has finally conceded, these attacks were the deliberate work of terrorists."
The administration counters that it has provided its best intelligence on the attack, and that it refined its explanation as more information came to light. But five days after the attack, Obama's ambassador to the United Nations, Susan Rice, gave a series of interviews saying the administration believed the violence was unplanned and that extremists with heavier weapons "hijacked" the protest and turned it into an outright attack.
She has since denied trying to mislead Congress, and a concurrent CIA memo that was obtained by The Associated Press cited intelligence suggesting the demonstrations in Benghazi "were spontaneously inspired by the protests at the U.S. Embassy in Cairo" and "evolved into a direct assault" on the diplomatic posts by "extremists."
Alongside defining the nature of the Benghazi attack, Congress is looking into whether adequate security was in place.
According to an email obtained Tuesday by the AP, the top State Department security official in Libya told a congressional investigator that he had argued unsuccessfully for more security in the weeks before Ambassador Chris Stevens, a State Department computer specialist and two former Navy SEALs were killed. But department officials instead wanted to "normalize operations and reduce security resources," he wrote.