Phi Beta Iota: We have been highlighting our couinterintelligence deficiencies since the 1990's, primarily focused on the need for religious counterintelligence, but also on the need to recognize that sub-state and non-state groups are legitimate threats in and of themselves. Today the US military it thoroughly penetrated by multiple networks from Opus Dei and the Mormons to radical Islamics and plain street gangs happy to not only receive advanced training, but access to easily stolen weapons–one of the dirty little secrets of the US military is how little control it has over the primary weapon of mass destruction on the planet, small arms (which we also like to sell liberally to anyone with cash and especially dictators).
It merits observation that Open Source Intelligence (OSINT) is a primary and often may be the only needed source to screen individuals who are properly debriefed upon entry. The Royal Canadian Mounted Police and Scotland Yard (Metropolitan Police of London) have done very well using OSINT in this fashion. In Afghanistan, biometrics may finally be getting a grip on our training multiple generations of Taliban fighters in how to kick our ass with our own knowledge of tactics and procedures.