The attack has caused huge embarrassment to the Afghan government, which claims that it has put in place a stringent mechanism for verification and background checks of all those seeking to join the police or the Afghan army, the BBC's Bilal Sarwary reports from Kabul.

BBC: Policewoman who killed US aide in Kabul 'is Iranian'

He implicitly recognized that "countering the al-Qaeda" narrative is as crucial to the well-being of the U.S. as is any stringent new airport security standard or detection mechanism.

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