The Northern Distribution Network through Central Asia won't be sufficient to get U.S. military supplies out of Afghanistan, senior U.S. military officials have said, saying that they need Pakistan to reopen its territory again to military transit. On Tuesday, the head of U.S. Central Command, General James Mattis, testified before the Senate Armed Services Committee, and said: “The withdrawal out of Afghanistan, we do need the ground line of communications through Pakistan.” That reinforced comments from last week by his colleague, General William Fraser, commander of U.S. Transportation Command, when he testified in front of the same committee. “With the amount of equipment we need to move ... we need the Pakistan [ground lines of communication] open,” Fraser said. “Because of the large numbers that we are talking about that we need to bring out in a timely manner.”

While the U.S. recently concluded agreements with all the Central Asian states for "reverse transit" -- bringing equipment out of Afghanistan when the U.S. and NATO start withdrawing in 2014 -- the generals' testimony emphasizes that won't be enough. General Mattis is going to Pakistan next week to try to negotiate a reopening of those routes, which have been closed since December, when a U.S. attack killed more than two dozen Pakistani soldiers.

General Mattis also had more to say about U.S. military cooperation with Central Asia in his written testimony (pdf). Despite the NDN not being enough on its own, Mattis is pretty upfront about it being the most important thing in the U.S.-Central Asia military relationship:

The Central Asian States are key to our Afghanistan campaign because the Northern Distribution Network (NDN) is a critical part of ISAF’s resupply and retrograde efforts. Over the past two years, the expansion of the NDN for transportation to and from Afghanistan has been one of the most significant areas of cooperation with our Central Asian partners. Central Asia shares similar threats from the Afghan border regions and CENTCOM military assistance focuses on building the capacity to fight against violent extremists. We are committed to preventing violent extremist organizations from using Central Asia as a base for terrorist operations and strengthening relationships based on shared understanding of the terrorist, criminal and narco-trafficking threats. Military assistance is focused on building counterterrorism capacity.

Our relationship with Kazakhstan continues to mature. We have recently signed new agreements for five years of defense cooperation and Kazakhstan continues to contribute to the Afghanistan mission. In 2012, Kazakhstan desires to expand the number of nations participating in Exercise Steppe Eagle, a peacekeeping exercise co-sponsored by Kazakhstan and the U.S.

Kyrgyzstan continues to be a key partner for U.S. efforts in Afghanistan and the region. The peaceful transition of power to President Atambayev demonstrated the Kyrgyz Republic’s effort to sustain democratic reforms. Our military relationship continues to improve, particularly in the areas of regional security and military security cooperation. Additionally, the Kyrgyz Republic aims to deploy a U.S.-trained peacekeeping mission within the next two years.

For Tajikistan building and maintaining counterterrorism, border security and counternarcotics capability to protect our mutual interests from the threat of violent extremist organizations are paramount to regional stability. In concert with our counterterrorism efforts, we are working with Tajikistan to improve disaster response. Tajikistan is committed to deploying their U.S.-trained peacekeeping battalion on a United Nations peacekeeping mission in 2012. We continue to explore options to facilitate the transit of goods and services in support of ISAF with this important partner.

Our security cooperation with Turkmenistan continues to develop along lines consistent with our mutual objectives of countering violent extremists and improving border security to counter narcotics trafficking.

Our relationship with Uzbekistan continues to improve in a deliberate, balanced way driven by regional security considerations, expansion of the Northern Distribution Network and mutual benefit. Security cooperation serves to provide increased U.S. access and influence in cultivating engagement for humanitarian and democratization efforts. We recently signed new agreements providing important new capabilities in support of Afghanistan and expect cooperation to continue to progress in a methodical step-by-step manner that addresses security threats of our mutual concern.

What jumps out most from this is the discussion of peacekeeping deployments. If Tajikistan really fields a peacekeeping battalion in 2012, I'll be shocked. The language on Kyrgyzstan (not specifying the size of the unit, timeframe in the next two years rather than ten months) is vaguer, but still: Kazakhstan, which is far more militarily capable than Kyrgyzstan or Tajikistan, has not been able to get its peacekeeping battalion in deployable shape, what chance do those countries have?