Just two months after the twin towers fell, the armies of the Northern Alliance marched into Kabul. The Taliban fled.

The triumph was total in the "splendid little war" that had cost one U.S. casualty. Or so it seemed. Yet, last month, the war against the Taliban entered its eighth year, the second longest war in our history, and America and NATO have never been nearer to strategic defeat.

So critical is the situation that Defense Secretary Robert Gates, in Kandahar last week, promised rapid deployment, before any Taliban spring offensive, of two and perhaps three combat brigades of the 20,000 troops requested by Gen. David McKiernan. The first 4,000, from the 10th Mountain, are expected in January.

With 34,000 U.S. soldiers already in country, half under NATO command, the 20,000 will increase U.S. forces there to 54,000, a 60 percent ratcheting up. Shades of LBJ, 1964-65. Afghanistan is going to be Obama's War. And upon its outcome will hang the fate of his presidency. Has he thought this through?

How do we win this war, if by winning we mean establishing a pro-Western democratic government in control of the country that has the support of the people and loyalty of an Afghan army strong enough to defend the nation from a resurgent Taliban?

We are further from that goal going into 2009 than we were five years ago.

What are the long-term prospects for any such success?

Each year, the supply of opium out of Afghanistan, from which most of the world's heroin comes, sets a new record. Payoffs by narcotics traffickers are corrupting the government. The fanatically devout Taliban had eradicated the drug trade, but is now abetting the drug lords in return for money for weapons to kill the Americans.

Militarily, the Taliban forces are stronger than they have been since 2001, moving out of the south and east and infesting half the country. They have sanctuaries in Pakistan and virtually ring Kabul.

U.S. air strikes have killed so many Afghan civilians that President Karzai, who controls little more than Kabul, has begun to condemn the U.S. attacks. Predator attacks on Taliban and al-Qaida in Pakistan have inflamed the population there.

And can pinprick air strikes win a war of this magnitude?

The supply line for our troops in Afghanistan, which runs from Karachi up to Peshawar through the Khyber Pass to Kabul, is now a perilous passage. Four times this month, U.S. transport depots in Pakistan have been attacked, with hundred of vehicles destroyed.

Before arriving in Kandahar, Gates spoke grimly of a "sustained commitment for some protracted period of time. How many years that is, and how many troops that is ... nobody knows."

Gen. McKiernan says it will be at least three or four years before the Afghan army and police can handle the Taliban.

But why does it take a dozen years to get an Afghan army up to where it can defend the people and regime against a Taliban return? Why do our Afghans seem less disposed to fight and die for democracy than the Taliban are to fight and die for theocracy? Does their God, Allah, command a deeper love and loyalty than our god, democracy?

McKiernan says the situation may get worse before it gets better. Gates compares Afghanistan to the Cold War. "(W)e are in many respects in an ideological conflict with violent extremists. ... The last ideological conflict we were in lasted about 45 years."

That would truly be, in Donald Rumsfeld's phrase, "a long, hard slog."

America, without debate, is about to invest blood and treasure, indefinitely, in a war to which no end seems remotely in sight, if the commanding general is talking about four years at least and the now-and-future war minister is talking about four decades.

What is there to win in Afghanistan to justify doubling down our investment? If our vital interest is to deny a sanctuary there to al-Qaida, do we have to build a new Afghanistan to accomplish that? Did not al-Qaida depart years ago for a new sanctuary in Pakistan?

What hope is there of creating in this tribal land a democracy committed to freedom, equality and human rights that Afghans have never known? What is the expectation that 54,000 or 75,000 U.S. troops can crush an insurgency that enjoys a privileged sanctuary to which it can return, to rest, recuperate and recruit for next year's offensive?

Of all the lands of the earth, Afghanistan has been among the least hospitable to foreigners who come to rule, or to teach them how they should rule themselves.

Would Dwight D. Eisenhower -- who settled for the status quo ante in Korea, an armistice at the line of scrimmage -- commit his country to such an open-ended war? Would Richard Nixon? Would Ronald Reagan?

Hard to believe. George W. Bush would. But did not America vote against Bush? Why is America getting seamless continuity when it voted for significant change?