In his United Nations speech on Tuesday, President Obama talked about the September 11 attack on the U.S. consulate in Libya and declared that "there should be no doubt that we will be relentless in tracking down the killers and bringing them to justice." What he didn't say is how relentless he'll be in tracking down the security lapses and intelligence failures that contributed to the murders. Let's say there's some doubt about that.

None of the initial explanations offered by the White House and State Department since the...