WASHINGTON - After 16 years of war in Afghanistan , experts have stopped asking what victory looks like and are beginning to consider the spectrum of possible defeats.
All options involve acknowledging the war as failed, American aims as largely unachievable and Afghanistan 's future as only partly salvageable. Their advocates see glimmers of hope barely worth the stomach-turning trade-offs and slim odds of success.
"I don't think there is any serious analyst of the situation in Afghanistan who believes that the war is winnable," Laurel Miller, a political scientist at the RAND Corp., said in a podcast last summer, after leaving her State Department stint as acting special representative for Afghanistan and Pakistan.
This may be why, even after thousands have died and over $100 billion has been spent, even after the past two weeks of shocking bloodshed in Kabul, few expect the United States to try anything other than the status quo.
It is a strategy, as Miller described it, to "prevent the defeat of the Afghan government and prevent military victory by the Taliban link" for as long as possible.
Though far from the most promising option, it is the least humiliating. But sooner or later, the United States and Afghanistan will find themselves facing one of Afghanistan 's endgames — whether by choice or not.
1. Nation-Building, Minus the Nation
"I'll tell you what my best-case scenario would be," said Frances Z. Brown, an Afghanistan expert at the Carnegie Endowment for International Peace.
That, she said, would see the US-led coalition abandon its efforts to impose a centralized state and instead allow Afghans to build their own state from the bottom up.
It would mean accepting a central government that acts more like a horse trader among local strongmen and warlords. American and allied troops would guarantee enough security to sustain the state. Afghans would figure out the rest for themselves.
Over time, ideally, Afghans might develop a functioning economy, then something like real democracy and, finally, peace and stability.
"But what we know from other cases is that this takes generations," Brown said. "So the 18-month time frames we've always had for Afghanistan are not realistic."
The perpetual occupation necessary for this to work might also doom it. Continued foreign aid incentivizes Afghan elites, who are already on the verge of splintering, to compete rather than come together.
This approach would involve tolerating the Taliban's presence in rural areas. And rolling crises would be built into this model, so Afghans would have to hope that they would somehow never derail the decades of progress needed before lasting change could take hold.
2. Starting Over
If Afghanistan were forced back to square one, it might, some scholars think, be able to rebuild itself from scratch.
After all, humanity lived for millenniums in something resembling low-grade anarchy. Modern nation-states grew out of that chaos only recently.
This would start with the effective collapse of the state and US withdrawal. Because the Taliban are too weak and unpopular to retake the country, as most analysts believe, Afghanistan would splinter.
Out of the ashes, local warlords and strongmen would rise up. Without the United States forcing them to take sides in an all-or-nothing war, they might eventually accommodate one another, and the Taliban. Their fiefs, once stable, could coalesce over years or decades into a fully realized state.
Research by Dipali Mukhopadhyay, a Columbia University political scientist, suggests that the warlords would gravitate toward the kind of state building that occurred in medieval Europe over centuries.
Jennifer Murtazashvili, a University of Pittsburgh political scientist who studies state building and failure, said the process might unfold more quickly and stably in Afghanistan . She has studied rural Afghan communities that outside the reach of the state, have begun reproducing the basic building blocks of one.
But hers is only a theory, untested in modern history.
3. The Somalia link Model
In a sign of how far hopes have fallen, the war-torn East African country of Somalia is increasingly being raised as worthy of emulation.
The Afghan government would retreat to major cities. Formally, it would switch to a federal system, as Somalia did in 2012. But power would effectively flow to whichever warlords and strongmen — potentially including the Taliban — rose up in the countryside.
This would, in theory, combine the first two models. The government could reconstitute itself as it mediated between local enclaves that would one day reintegrate with the state.
"This is the outcome we have de facto ended up with, but not in a peaceful sense," Murtazashvili said. The government is receding and the warlords are rising, but the two are in conflict.
The Somalia model would manage that process of disintegration, like crash-landing a plane rather than waiting for it to fall from the sky.
It would leave communities to find their own peace with the Taliban, which some in remote parts of the country are already doing.
In Somalia itself, this model has found mixed success. Security has improved nationwide, but a devolving state has been left unable to root out extremists, who still carry out devastating attacks.
4. A Peace That Satisfies No One
The paradox of peace deals is that, while all sides benefit, each fears that it will not do as well as it could — or that its enemies might do too well. This gives each an incentive to block all but the perfect deal, a dynamic so pronounced in Afghanistan that, in 16 years, talks have never advanced far enough to make clear what each side considers acceptable.
"I doubt the Taliban has even given any thought at a higher level to what a government looks like that it could have a stake in," said Courtney Cooper, a Council on Foreign Relations analyst.
The fear of losing out is not misplaced. Afghan elites already squabble over control of ministries and lucrative patronage networks, and their infighting grows as those resources shrink. In any peace deal, they would need to surrender many or most of those resources to the Taliban.
The Taliban, too, would probably need to surrender or curtail their hopes for dominating Afghanistan . That could anger the extremists rising in the group's ranks.
And any US president would risk a political backlash for appearing to usher the Taliban back into power. Veterans and military leaders might reasonably ask what they had fought for.
The clearest winner of any deal might be the Afghans themselves, but they are largely at the mercy of political actors for whom peace is risky.
5. A Post-American Civil War
There is a more pessimistic version of the collapse-then-rebuild model in which warlords compete until one prevails over all.
Afghanistan itself offers a particularly vivid example of this scenario: After the 1992 collapse of the Soviet-backed government there, the country was gripped by a terrible civil war.
If the Americans abandoned the government now in place, that history could repeat.
"There is a strong possibility that this county could splinter, and not in consensual ways," Murtazashvili said.
That war culminated, in 1996, with one faction prevailing: the Taliban. It then sheltered al-Qaida, prompting the US-led invasion and the war still raging all these years later.
That history, too, could repeat. Research by Barbara F. Walter, a political scientist at the University of California, San Diego, has found that extremists tend to prevail in civil war, and to do better as the war drags on. If the Americans exit Afghanistan , it might not be for long.
6. Perpetual Stalemate
The likeliest outcome may be allowing the status quo to continue, even as all sides suffer under rising violence.
Neither the government nor the Taliban are strong enough to retake control. Outside actors like the United States and Pakistan may be unable to impose their vision of victory, but they can forestall losing indefinitely.
Foreign aid can sustain the government, even as its control of the country shrinks. There is little to stop the Taliban from carrying out ever more brazen attacks in the capital. The death toll, already high, would probably rise.
Eventually, the stalemate would almost certainly break, hurtling Afghanistan into one of its possible endgames. But it is difficult to say when.
"It's hard to think of an analogous case," said Brown, the Carnegie Afghanistan expert.
Few modern wars have raged this long, this destructively and with this much outside intervention. If there is an obvious way out, history does not provide it.