The Army keeps 45 days worth of fuel on the ground in Afghanistan so that operations can withstand severe disruptions to its supply lines, Stevenson said.
If the southern routes were shut down, the U.S. would increase its use of airdrops and flow more in from the north. However, that route takes much longer and is more expensive, Stevenson said.
Smaller disruptions already frequently delay the delivery of supplies. For example, a sit-down strike in Karachi is keeping supply trucks from getting to the port, Stevenson said. He expects the strike to last a couple of days.
Of the supplies it delivers by land, the U.S. brings in 60 percent to Afghanistan from the north through Central Asia and the Baltic states and 40 percent from the south through Pakistan. There, supplies arrive in the port of Karachi and travel over land by contractor-driven trucks.
The goal is to increase supplies coming in from the north to 75 percent, Stevenson said. "We're not there yet."
Of course, much of the northern route goes through Russia. Reset or not, I'm not comfortable with that. Our efforts to get another route across the Black Sea that avoids Russia will diversify our supply routes.
Also, it is noteworthy that we don't rely on just-in-time delivery of key supplies and maintain at least some iron mountains in case we lose a supply route and need to switch emphasis to another.
Of course, I'd be happier still if we had a friendly government in Iran that allowed for a supply route that way.