"The fact is, we had four dead Americans," former Secretary of State Hillary Clinton famously exploded during a January Senate hearing on the Sept. 11, 2012, attacks against the U.S. consulate in Benghazi, Libya. "Was it because of a protest or was it because some guys out for a walk one night who decided they would go kill some Americans? What difference at this point does it make? "It is our job to figure out what happened and do everything we can to prevent it from ever happening again."

Clinton's outburst was portrayed afterward by the media as an example of her strength against Republican critics in Congress. But that narrative was rendered obsolete by testimony Wednesday before the House Oversight and Government Operations Committee by a career U.S. diplomat posted in Libya during the assault. The first part of the answer to Clinton's ringing question is now clear: The Obama administration's ridiculous claim that the attacks were a response to an anti-Muslim YouTube video undermined U.S. efforts to figure out what actually happened.

President Obama, Clinton and White House spokesman Jay Carney repeatedly condemned the video for days afterward, with then-U.S. Ambassador to the U.N. Susan Rice even insisting a week after the attack that it was a "spontaneous" reaction to anti-video protests in Cairo. Obama mentioned the video repeatedly in a U.N. speech two weeks after the attack.

But at Wednesday's hearing, Gregory Hicks, the 22-year Foreign Service veteran who was the deputy chief-of-mission at the U.S. Embassy, testified that it was clear from the outset that the assault was a pre-planned, coordinated terrorist attack. "The YouTube video was a nonevent in Libya," said Hicks. Hicks' testimony was reinforced when Rep. Trey Gowdy, R-S.C., read from a State Department email sent a day after the attack. Acting Assistant Secretary of State Beth Jones wrote this in the email: "I spoke to the Libyan ambassador and emphasized the importance of Libyan leaders continuing to make strong statements," adding, "I told him that the group that conducted the attacks, Ansar al Sharia, is affiliated with Islamic terrorists." Copied on the email were Cheryl Mills, counselor to Clinton, State Department spokeswoman Victoria Nuland and Undersecretary of State for Management Patrick Kennedy.

Shown a video of Clinton's "what difference does it make" question, Hicks countered that such obfuscation had major consequences. "I definitely believe that it negatively affected our ability to get the FBI team quickly to Benghazi," said Hicks. And indeed, although Obama promised last September that the attackers would be brought to justice, the FBI investigation has progressed at a snail's pace, with next to nothing to show for the effort.

Five days after the attack, Libyan President Mohamed Magarief publicly stated it was premeditated, so, according to Hicks, Magarief "was insulted in front of his own people, in front of the world, his credibility was reduced," when Obama trotted out the video illusion. Magarief then denied the FBI access to the scorched compound for a crucial 17 days. Since the area wasn't secure during that period, vital evidence likely was lost forever. So to answer Clinton's question, one difference made by the false video narrative is that Americans possibly will never know the full truth of about who murdered Ambassador Chris Stevens and three of his brave colleagues in Benghazi.