The flash of the Taliban's heavy machine gun catches the rebel commander's eye first, as he peers across the Afghan front line from his sandbag perch. When he sees the Taliban soldiers themselves, walking in full view of his gun sights, he orders his firepower unleashed.
The result illustrates just one of the perils of US strategy as focus shifts from the air war to aiding a Northern Alliance ground war: relying on a ragtag force that has its own military aims.
"Are you loaded? Are you ready?" Major Khan Sayed raps into his walkie talkie. "Yes, I'm ready," his lieutenant radios back from the cockpit of a nearby armored personnel carrier, which is missing its wheels. "Watch and see where it goes." The first missile from the 70mm gun carves a fiery arc across no-man's land, and explodes 20 yards to the left of the Taliban position. After Major Sayed radios advice, the next round lands 20 yards to the right. Another two rockets fall short.
"Shoot two or three more," Sayed orders. But after a brief pause, the reply comes back, thick with failure: "We can't," the gunner says. "The barrel is stuck. It won't go up or down."
As America enters the second month of its air campaign with no clear military gains, the US is shifting from pinpoint air strikes to backing a proxy band of rebels in complex ground war. In the past two weeks, US forces have been bombing targets of increasing importance to the alliance, providing the rebels with funding for Russian-supplied weapons, and boosting the number of clandestine American personnel on the ground with the rebels.
Alliance Foreign Minister Abdullah Abdullah says the US now appears to understand that it has little choice but to ally with the rebels on the ground, who have fought the Taliban for years.
"You can't hope for something out of the sky to do the job," Dr. Abdullah says. "That reality is being recognized more and more by the Americans on a daily basis. We had asked for better coordination, and now we see it is improved."
The alliance is a loose grouping of ethnic minorities - bound only in their opposition to the Taliban - who may have trouble ruling the entire country. That's one reason that US policymakers kept them at arm's length at first.
"There are two different wars going on simultaneously, which yield their own fruits," explains the Vermont-based air-power and defense analyst William Arkin. While the strategic air war at the start took up to 90 percent of the US effort, the "other war to support the Northern Alliance and attack the Taliban in the field" is now coming to the fore.
Just yesterday, a white twin-engine plane landed at a new airstrip in Gulbohar, 40 miles north of Kabul. At least five Caucasian men got off the plane, dressed in photo vests worn by journalists - a ruse used in Somalia as a cover for US intelligence agents. When a reporter asked if they were journalists, they would not respond. Moreover, the plane's registration number, N6160, appeared to be illegitimate. It was first registered to a single-engine acrobatic aircraft in 1976, though the certificate of registration has since been revoked.
Meanwhile, Defense Secretary Donald Rumsfeld says hundreds more special forces men are "cocked and ready" to operate in Afghanistan, though severe weather is slowing their effort.
But some analysts question whether the US can embrace such an unprepared armed group of rebels on the ground to achieve its aims.
"Is this a tenable military force?" Arkin asks, listing current policy considerations. "Maybe we had a too-romantic idea of the Northern Alliance and what they are capable of."
The immediate effect of the bombing on the Taliban has been a boost in their morale, because they are surviving the bombing. "But that will wear off," Arkin says. "The question is: Can America run the marathon?"
There are signs that the US is stepping up its pace of warfare. Just a few weeks ago, the US discouraged an advance on Kabul, lacking a political gameplan. But over the weekend, Mr. Rumsfeld said it was "mindless" to slow the war for political reasons: "I don't think it's possible to manage the war campaign on the ground under a political timetable" of installing a post-Taliban government.
The US has stepped up its air attacks on Taliban positions north of Kabul and around the northern city of Mazar-e Sharif. The alliance reported gains over the weekend, saying it had captured the Aq Kubruk district south of the city and killed 20 Taliban soldiers when 800 Taliban fighters defected.
While pinpoint US strikes are "having an effect," the increased US help on the ground - including at least 20 uniformed Americans on the northern front - reflects a new calculation in Washington, says alliance General Babajan.
The big change came with the killing in Afghanistan a week ago of opposition chief Abdul Haq, an ethnic Pashtun - the group that dominates the Taliban. He had been key to US-led political efforts to form a future government. "Now the Americans understand that the only way to succeed is to strike militarily and work very closely with the Northern Alliance," Babajan says.
Privately, however, rebel commanders say their forces are far from prepared to move on strategic objectives.
During a weekend military exercise for hundreds of troops in Jabal Saraj, some alliance fighters had trouble operating their guns. When the regional commander, Gen. Bismallah Khan, ordered them to fire, most did. But one 70mm cannon on an armored car first had to be lifted into place. Vehicles stalled, belching thick fumes of exhaust. And the back-blow from a 106mm recoilless cannon covered General Khan and his entourage with a thick cloud of eye-squinting dust.
Episodes like this do not mean the troops are unprepared for battle, however, says Arkin. "The history of fighting in Afghanistan is man to man, slow-moving combat," he notes. "The fact they can't shoot artillery accurately, or their tanks can't do pirouettes, or they are not at NATO standard, does not necessarily mean they are not capable, or that the opposition is not credible. "We have to shift our terms," he says, when assessing the Afghan warrior, "and adjust our Western standards."