Recent developments in Pakistan suggest that the country could be close to reopening its borders with Afghanistan to military supply lines if the right conditions are met. The stipulations include an end to drone strikes on Pakistani territory, an apology for the deaths of Pakistani soldiers in November drone strikes, a tax on NATO convoys, and a ban on transporting weapons and ammunition through Pakistan. 

Pakistan's government, NATO, and U.S. officials must all approve the terms before operations can resume. Political and religious groups within Pakistan appear to be pressuring to avoid compromise. In March, the Taliban threatened to kill Pakistani lawmakers and their families if they supported reopening the country's borders to NATO shipping and to “publicly slaughter” drivers of NATO supply vehicles.
The reopening of supply lines through Pakistan would be a welcome development for the United States and the International Security Assistance Force (ISAF), which are scheduled to withdraw their troops from Afghanistan by the end of 2014. Prior to closing its border to military supply transit, Pakistan was host to 90 percent of the traffic. As a result of the closure, the Northern Distribution Network (NDN), an alternative supply route through Russia and Central Asia, is already handling increased traffic. Close to 75 percent of ground sustainment cargo and an estimated 40 percent of all cargo is currently shipped via the network, according to U.S. Transportation Command. 
But U.S. military officials have stated that it alone will not be sufficient for moving ISAF equipment and personnel out in the compressed amount of time available. Using the NDN also comes at a much higher cost and requires a longer transit time than the route through Pakistan.
Moreover, doubts persist about key Central Asian countries' willingness and ability to host more traffic than they already are. Almazbek Atambayev, Kyrgyzstan's new pro-Russia president, has consistently stated that the United States would have to leave the Manas base in Kyrgyzstan, a key link in the NDN, in 2014 when the lease expires. He has argued, in the words of one journalist, that the U.S. base puts Kyrgyzstan "at risk of retaliatory strikes from those in conflict with the United States." There is some indication that Kyrgyzstan may be willing to reconsider, but as yet Atambayev appears to be sticking to his guns. 
Uzbekistan, a hub for NDN operations that has the best railroad network in Central Asia, could also prove unwilling. EurasiaNet reported that commercial sources familiar with operations on the NDN say that Uzbekistan is “continuously uncooperative” in facilitating the shipment of goods to Afghanistan and that the hassles are so great that some Pentagon contractors try to avoid shipping through the country. 
Even if negotiations with Pakistan are successful, ISAF may still need to ship significant supplies via the NDN. And all countries involved in transporting the military materiel stand to profit. The U.S. Department of Defense already pays approximately $500 million per year to Central Asian states participating in the Northern Distribution Network and according to EurasiaNet, the new National Defense Authorization Act earmarked an additional $90 million for countries that provide the U.S. military with “logistical, military, and other support including access provided by that nation.”