Why U.S. Troops Must Stay in Afghanistan

Will the United States continue to conduct counterterrorism operations in South Asia? That question is central to any discussion about U.S. troop presence and mission in Afghanistan. The answer can be yes only if we pursue and support the current strategy, retaining roughly 68,000 troops in Afghanistan into 2014 and about half that number thereafter.

Amateurs can discuss imaginary, over-the-horizon “light footprint” strategies. Professionals must consider logistics. Physics and military reality dictate the minimum number of troops needed to have any U.S. presence in Afghanistan without inviting calamities worse than the events in Benghazi, Libya. The presence of U.S. forces in Afghanistan alone permits counterterrorism operations in Pakistan. It’s this simple: Either we keep the necessary number of troops in Afghanistan or operations against al-Qaeda and its affiliates in Afghanistan and Pakistan cease.

The principal terrorist concentrations in South Asia are in Pakistan’s federally administered tribal areas. Al-Qaeda and affiliated groups have sought safety in Afghanistan primarily in Konar and Nuristan provinces. U.S. forces could target terrorists without maintaining a ground presence in three ways: using armed Predator drones, special mission units or precision-guided munitions dropped from manned aircraft. Without bases in Afghanistan, the tyranny of distance rules out the first two options; the requirement for accuracy and certainty rules out the last.

North Waziristan is more than 600 miles from the nearest coastline; the other sanctuaries are farther. The U.S. Air Force reports that armed Predator drones have a range of about 1,150 miles — not enough to get to Waziristan and back again from the coast, much less to orbit and observe a target. Special mission units would have to parachute from transport aircraft because no helicopter in the U.S. inventory can fly that far. But they could not return because aircraft cannot land in the mountains of Eastern Afghanistan or in Pakistan. Manned aircraft can drop precision weapons on targets in Afghanistan, but they fly too fast to loiter over potential targets. Their bombs hit precisely what they are aimed at, but fast-moving aircraft cannot ensure that the target was actually there. There is no over-the-horizon solution to targeting terrorists in South Asia.

Bases in Afghanistan obviate all these problems. U.S. forces operating from Khost, Jalalabad and Kandahar can strike targets in Afghanistan (or Pakistan) with Predators and special mission units. Such operations have been critical to the success of counterterrorism operations in this region, including the killing of Osama bin Laden (Abbottabad is about 150 miles east of Jalalabad, 750 miles from the Indian Ocean).

The minimum U.S. footprint to sustain counterterrorism operations requires bases near Jalalabad, Khost and Kandahar to reach known terrorist havens (Khost and Jalalabad are less than 100 miles apart but are separated by a 10,000-foot mountain range). Each base requires an airstrip to fly Predators and move supplies by air. Each must also have aircraft ground crews and support the special mission units.

Base security and support impose serious troop requirements. These bases are in dangerous places, and we surely will not entrust the protection of U.S. personnel to local forces as we did in Benghazi. Securing the perimeter would require at least two companies of soldiers (alternating guard duty) and a company-size quick-reaction force — a battalion, in other words. Each base must also have the helicopters needed to move around and conduct operations — at least a combat aviation battalion — and a field medical facility able to handle severe trauma. That adds up to one combat brigade (3,500 soldiers) and one combat aviation brigade (5,000 to 6,000 soldiers).

That’s about 10,000 troops — without counting the supply or command and control of these forces. Even if we supply each base directly by air from outside Afghanistan, with no facility near Kabul, each base still needs logistical elements, probably at least 3,000 to 5,000 combat service support troops. The most idealized version of the limited counterterrorism footprint, therefore, is around 15,000 troops. At that strength we would not be able to advise, enable, support or rely on the Afghan National Security Forces (ANSF). Since they, like our NATO allies, depend on U.S. enablers such as reconnaissance, helicopters, medevac and route-clearance packages, most of their operations would cease.

Thus this footprint would not allow our troops, our allies or the Afghans to maneuver. At best our troops and bases would become isolated islands focused on protecting themselves and irrelevant in the fight against al-Qaeda. At worst they would take losses much greater than we suffered in Benghazi.

This minimum counterterrorism footprint requires basic stability near our long-term bases to have any effect. The ANSF must sustain that stability but can only do so supported by U.S. advisers and enablers. Advising the three Afghan National Army corps and Afghan National Police zones around the bases requires at least three advise-and-assist brigades — one per corps and zone — plus support units. Such brigades are smaller than combat brigades, about 1,500 each. They must, in this concept, be located with our counterterrorism forces to avoid having to secure additional bases.

Now we’re up to around 21,500 troops total, without a central headquarters near Kabul or any reliable means of moving by road between our bases. In the real world, neither of those conditions makes sense. Adding up the security forces for a base near Kabul, a theater headquarters, route-clearance packages, theater logisticians and other ancillary units is likely to push the requirement above 30,000.

At that level U.S. forces in Afghanistan could do nothing beyond the minimum necessary to allow us to continue counterterrorism operations in South Asia: no nation-building, no effort to affect the Afghan political process or help the Afghans secure presidential elections in 2014, no development assistance; only defensive operations against the Taliban and other insurgent groups from three bases.

Moving toward this long-term posture in 2013 will likely ensure its failure. As we fall below 68,000 troops, we will have to withdraw from important terrain and lose the ability to maneuver. Our forces won’t be able to operate in most of southern Afghanistan, conduct offensive operations or help the ANSF consolidate and mature. We must create basic stability in 2013 that the ANSF can sustain to set conditions for any long-term U.S. counterterrorism operations. Doing so requires two things this White House appears to want to avoid: keeping U.S. force levels where they are for the next two years; and implementing a serious political strategy aimed not at our enemies but at the people we need to be our long-term partners.

The United States can stabilize Afghanistan if it maintains around 68,000 U.S. troops in Afghanistan into 2014, dropping to over 30,000 thereafter (about what we have in Korea). The idea that the war is inevitably lost is a convenient mask behind which decision-makers hide to deflect responsibility for pulling out troops who are making a real difference.

We have argued that the current defeatism about Afghanistan is overdrawn and unfounded. But it is more important for Americans to internalize a simple fact: We must either stabilize Afghanistan at this minimum level or abandon the fight against al-Qaeda and its allies in South Asia. Any alternative “light footprint” strategy is a dangerous mirage.