As Afghanistan's Taliban regime hunkers down - despite heavy US-led airstrikes and backing for key opposition forces - debate here is intensifying over whether to deploy larger numbers of American ground troops in the war on terrorism.
The Pentagon has made it clear that it will not rule out the use of sizeable numbers of US ground forces, and military experts say that planning for such a contingency is almost certainly under way.
"We do have a very modest number of ground troops in the country" to help resupply resistance forces and target the Taliban, Defense Secretary Donald Rumsfeld said Tuesday, praising the US troops for their efforts.
"We do not have anything like the ground forces we had in World War II or in Korea or in the Gulf War, but nor have we ruled that out," he said.
Britain has also pointedly left open the option of deploying ground forces, said British Defense Minister Geoffrey Hoon, who joined Secretary Rumsfeld at a Pentagon briefing.
Ordering US troops into a major ground war in Afghanistan would carry vast political and diplomatic risks, threatening to unify Afghans and other Muslims against US and allied forces, which in turn could become entangled in a protracted guerrilla war, experts say.
Nevertheless, as the antiterrorist campaign in Afghanistan unfolds, military strategists agree that it appears increasingly likely that without some greater commitment of US ground troops, the Taliban could continue to cling to power indefinitely, hampering US efforts to track down Al Qaeda terrorist leaders.
"I don't think that the Northern Alliance by themselves can pull it off," says Mackubin Owens, a professor of strategy and force planning at the Naval War College in Newport, R.I., referring to the main anti-Taliban opposition force.
On Capitol Hill, some lawmakers have also urged the Bush administration to dispatch larger numbers of ground troops. "It's going to take a very big effort, and probably casualties will be involved," said Sen. John McCain (R) of Arizona in a television interview this week.
A range of options
While Pentagon officials decline to discuss specific plans for sending more ground troops to Afghanistan, experts with military backgrounds outside the government describe a range of options. Such strategists are widely divided, however, on the necessary size, goals, and timing of an attack by US ground forces - largely because they differ in their assessment of Taliban strength and tenacity.
Some experts contend that a relatively small US contingent could be deployed, essentially to leverage Afghan resistance forces and US Special Operations troops, and tip the balance of power against the Taliban.
For example, Washington could deploy one or two light infantry divisions, a total of about 30,000 troops, as part of "a general offensive toward Kabul and Kandahar," says Professor Owens, a former marine.
Drawn from Army units - such as the 10th Mountain Division, the 25th Infantry Division, and the 82nd Airborne Division - such troops would help seal off major cities and aid their capture by opposition forces, while also supporting raids on terrorists by American commandos, he says. Working with the opposition, the added US firepower could strike a serious enough blow to the Taliban to encourage its supporters to defect, according to Owen.
Under such a scenario, US forces would aim less to wipe out the Taliban than to steadily suppress it, says Tom Nichols, another Naval War College strategist who agrees that "a larger [US] ground presence" will be needed. "This isn't the Gulf War II," he says. "This is a long, messy, dragged-out business."
Yet other strategists argue that a massive invasion force of up to 500,000 or even 1 million US troops would be needed to achieve the stated US goals of decisively defeating the Taliban, rooting out Al Qaeda, and leaving in its place a more stable, US-friendly political regime. "To defeat the Taliban and crush Al Qaeda is going to require large-scale American ground forces," says John Mearsheimer, co-director of the Program on International Security Policy at the University of Chicago, adding that at least 500,000 troops would be needed.
So far, the Taliban has shown few signs of cracking from internal dissent, he says. On the contrary, "the Taliban has given every indication that it is in for the long run and will be a formidable foe against the Northern Alliance and our [US] Special [Operations] Forces," Mr. Mearsheimer says.
The Taliban are able to resupply themselves, thanks to relatively porous borders with Pakistan, while surviving on large stored stocks of ammunition, weapons, fuel, and food, he says. Meanwhile, the Northern Alliance "is badly outnumbered, badly equipped, badly led, and deeply despised in the area we want them to conquer."
Yet while sending in an overwhelming number of US ground troops could succeed in defeating the Taliban and eliminating Al Qaeda, Washington would face a major obstacle pulling out, leaving the possibility US forces could be bogged down in Afghanistan for years, warns Mearsheimer.