In the 1990’s, two Soviet moles, Aldrich Ames and Robert Hanssen, penetrated, respectively, the CIA and the FBI. In the wake of their exposure and capture, strict new counterespionage procedures were said to have been put in place to prevent a recurrence of a calamity that destroyed America’s human intelligence in the USSR and its successor states.

But when it came to light last fall, the case of Nada Nadim Prouty, a Lebanese immigrant who moved from sensitive positions in the FBI to sensitive positions in the CIA, even as she maintained close ties to Hizballah and even as she arrived in the U.S. on the basis of a fictitious marriage, exposed the fact that internal security remains a critical weak point.

Michael Sulick, the head of CIA human intelligence, has openly expressed worry about the harm that could be wrought by an al Qaeda mole in CIA ranks. The Prouty case is only one piece of evidence that this is not an idle fear.

The Evening Standard reports that “four police officers in Britain’s top force are reportedly under close secret service surveillance after being identified as Al Qaeda spies.” MI5, the British equivalent of the FBI, believes their function was to alert al Qaeda of pending anti-terror raids.

Clearly, we are facing a sophisticated adversary. The question is: are we sophisticated ourselves?