Explain to Me Why Sending Private Security Contractors to Afghanistan Makes Sense

Walter Pincus reported this morning that the Pentagon is getting out the contractor playbook once again, this time to "provide armed security guards to protect Forward Operating Bases in seven provinces in southern Afghanistan (Helmand, Kandahar, Nimruz, Zabol and Uruzgan)."  According to Pincus:

The hired guards would be required to carry out surveillance of the perimeter of the base from fixed positions to see whether someone is attempting to sneak inside. They are also to engage in counter-surveillance, watching to see whether someone is monitoring who enters and leaves the base. The contractor guards are also to be available to protect supply routes, facilities, convoys and property.

The guards would be required to employ "the appropriate force to neutralize any threat," particularly from individuals trying to enter illegally "with the intent to harm personnel or damage facilities and equipment . . . but are NOT authorized to undertake offensive operations."

There may be good reason for deploying private security contractors to rural Afghanistan, but it's hard to imagine worse optics.  In the coming months, the U.S. will have to maintain a delicate balancing act in Afghanistan -- doubling efforts, while still striving to keep the faith of it's people.  Introducing PSCs -- lightening rods for controversy in the Muslim world -- into an already volatile situation just seems nonsensical, especially on the heels of the announcement that troops from the 10th mountain division are headed to Kabul, and not the surrounding countryside where the insurgency is based (which may be an indicator of how precarious the security situation has become).  Why are we sending U.S. troops to Kabul and contractors to the heart of the insurgency?