With stunning rapidity, the Afghan war has shifted south, presenting the Pentagon with new challenges and opportunities.
Yet as fighting shifts to southern Afghanistan, the Taliban gains some advantages, facing U.S. and anti-Taliban forces in a region it knows well. Because there is no southern equivalent to the Northern Alliance, the United States may have to bear a heavier burden of fighting in the south, a battle that is likely to take on a guerrilla character.
Even if the Taliban stronghold of Kandahar were to fall, few people are willing to assume that the government's troops would fold immediately. Driven by religious fervor, ethnic cohesion and a longstanding tradition of guerrilla warfare, they may well take to the hills to fight and regroup.
This scenario has played out through history, as in the 19th century when ethnic Pashtuns, the same tribe that makes up much of the Taliban, wiped out a colonial British fighting force trying to escape through the Khyber Pass. "The stamina of the Afghans for guerrilla warfare is proverbial," said Shamim Akhtar, an international relations expert at Karachi University in Pakistan.
During the 1980s Soviet occupation of Afghanistan, many of the fighters who now lead the Taliban became expert at hiding in remote mountain regions and descending to strike enemy troops and convoys. Now by moving out of the country's cities, including the capital, Kabul, the Taliban may be returning to the type of hit-and-run warfare it knows best.
But the drive south also brings benefits to the U.S.-led military coalition. Milder winters, better roads and flatter terrain make southern Afghanistan a more promising theater than the mountainous and increasingly snowbound north. Kandahar, the southernmost major Afghan city, is the closest key target to the USS Kitty Hawk, a carrier loaded with helicopter-borne Army Special Forces in the Arabian Sea.
U.S. officials refuse to detail their military plans. But two goals emerge clearly in interviews with national security officials. One is to keep up the pressure on the Taliban through the winter. The other is to avoid the kind of ponderous ground assaults that became ready targets for guerrillas during the Soviet occupation.
"You don't want to have a four- or five-month lull," said Andrew Krepinevich, a military analyst with the Center for Strategic and Budgetary Assessments, a Washington-based think tank.
Once the Taliban is out of the way, U.S. military action would presumably focus on al-Qaida terrorist forces in the south. Though the network run by Osama bin Laden has had a large presence in the Kandahar area, many of its operatives are thought to have fled the country with the onset of U.S. air attacks that fell particularly heavily on al-Qaida camps.
Remaining terrorist strongholds could be subject to commando-style raids, most likely launched from the Kitty Hawk. With the spring thaw next year, operations could shift to the eastern mountains where most of the al-Qaida camps are located.
If the rebel alliance continues to push south, "it will be an unfamiliar and hostile environment. Advances will be difficult," predicted retired Pakistani Lt. Gen. Kamal Matinuddin.
Meanwhile, U.S. military and intelligence officials will work through various Afghan faction leaders to promote defections from the Taliban to rival tribes that have the same ethnic Pashtun base as the Taliban but favor a less militant form of Islam.
The United States appears to be pursuing a multi-pronged strategy, Krepinevich said: to promote defections from the Taliban; exploit warmer weather in the south for continuing air operations; and to exploit the proximity of the Kitty Hawk to conduct more commando raids.
With snow on the ground, Krepinevich said, U.S. spy satellites and pilotless drone aircraft may have an easier time detecting people in remote mountain redoubts.