Vetting of Afghan Security Force Members

On a rare occasion we will read about an Afghan security force member turning his weapon on members of the coalition (American, German, French, etc.) and trying to kill them.  The possibility of the Taliban trying to infiltrate the Afghan security forces for this purpose is troublesome and it would appear that ISAF is taking steps to mitigate the threat through a vetting process.  Read more in "Afghan forces undergo stricter vetting by NATO commanders", USA Today, February 18, 2011.