I've had a chance to check for you -- on the issue of supply lines from Pakistan into Afghanistan. That is a very real area of concern for our commanders in Afghanistan because 75 percent of all of our supplies for our troops in Afghanistan flow either through or over Pakistan, including 40 percent of all fuel, which comes from Pakistani refineries.
But at least we have an option of going north at higher cost (but at Russia's pleasure, ultimately).
This is one reason why I am uncomortable with putting too many troops into Afghanistan. They are potentially hostage to politcial upheavals.
But perhaps this real world example will finally end the chowderheaded talk of pulling our forces out of most of Iraq and concentrating them in the friendly Kurdish areas where they will be just as vulnerable to being cut off from sources of supply.