The ethnic Uzbek warlord said that the final assault had started around 4 p.m. and that within two hours the Taliban had abandoned their defensive lines and evacuated the city. When asked if there were still any Taliban in the city, Dostum said the only Taliban in Mazar were the wounded left behind in the city’s hospitals. “We have the airport, we have Mazar, we have everything,” he said through an interpreter. Later the Taliban-controlled Afghan Islamic Press confirmed that opposition forces had entered the city “after heavy American bombing” of Taliban positions.

Dostum’s claims cannot yet be independently verified, but if they are true the capture of Mazar-e Sharif would be the first tangible victory in America and its allies’ war against the Taliban and Osama bin Laden. (Pentagon officials today refused to confirm the Alliance statements, with spokeswoman Victoria Clarke describing the situation around Mazar-e Sharif as “fluid” but “encouraging.” “Until things settle and we see where forces are after a day or two, our inclination is to withhold comment,” Clarke told a briefing in Washington today. However, NBC News reported Friday night that unidentified U.S. officials had confirmed the capture of the city and said hundreds of Taliban fighters had been taken captive.)

NBC also cited uncorroborated reports that two Taliban commanders in the city had turned on each other and that their forces were fighting among themselves, while others were committing “atrocities against civilians.” Such a scenario is possible, given the complex ethnic makeup, and shifting loyalties of the factions taking part in the war in northern Afghanistan.

The Taliban forces in Mazar were mostly ethnic Pashtuns, together with Arab and Pakistani volunteers. The city’s population, by contrast, is similar to that of the Northern Alliance forces advancing from the south: almost entirely ethnic Tajik, Uzbek and Hazara.

Alliance spokesmen say the Americans, dressed in Afghan garb, have been shuttled by helicopter between the headquarters of the three Alliance generals, calling in airstrikes as needed on different sections of the front line.

If Mazar has in fact fallen, Alliance spokesmen say they should soon be able to sweep Taliban forces from the border of Uzbekistan, 40 miles to the north, and secure the area for the delivery of humanitarian and military aid. The only bridge and major ferry port connecting northern Afghanistan to the rest of Central Asia are in Uzbekistan, and their reopening is essential for both supply of Alliance forces and the survival this winter of more than 400,000 internally displaced persons in the north of the country.

Once the area around Mazar is secure, the Alliance ambassador to Uzbekistan, Mohammed Hashan-Saad, told NEWSWEEK that its forces would most likely turn eastward, pushing toward the strategic city of Kunduz, some 90 miles away. If Kunduz fell, the frontline town of Taloqan would lose its main source of supply, and could possibly fall to Alliance forces pushing from the east. The fall of these two towns would link the divided Alliance forces, giving them control of the north of the country, easier lines of communication and supply, and, most important, a number of airfields that could be used as forward bases for U.S. and allied aircraft.

But all these grand plans still rest firmly in the distant future. For now, the question is: Can the Alliance hold on to Mazar in the face of Taliban counterattacks, and its own past history of factional infighting and defections?

The Uzbek town of Termiz, just across the Amu Darya River from Afghanistan, has been shaken by distant U.S. airstrikes in recent days, but the border is still not free of Taliban forces, and even if the Alliance can secure the bridgehead and ferry port, it is not clear when aid and supplies will start flowing south. Uzbekistan’s government, fearful of an influx of hungry Afghan refugees, has so far refused to open the bridge and has only recently agreed to allow humanitarian aid to ferry across the river on barges once used to supply Soviet forces in the Afghanistan. The first aid barges were planned to cross the river sometime next week, but international officials say the movement has been delayed due to security concerns on the part of the United Nations. The border has been sealed since the fall of Mazar in 1998, and no one on either side of the border is certain if the ferry ports have been mined and, if so, who has the maps.

So while Mazar may have fallen, it may be days, or even weeks, before the growing army of journalists and aid workers camped in Termiz are able to cross the river to that often-promised city.