What if the United States pulled all its troops out of Afghanistan?
The general assumption is that as Washington and Kabul work to hammer out a long-term security agreement, a way will be found to maintain a U.S. troop presence after 2014.
The two sides have reached a preliminary agreement on a deal. But a key U.S. demand -- that its troops be granted immunity from prosecution under Afghan law and be tried only in the United States -- remains a major sticking point.
Afghan President Hamid Karzai has put the final decision on a deal to a Loya Jirga -- a traditional gathering of tribal, ethnic, and religious leaders -- that will meet and give its verdict next month.
Washington has made clear that the "zero option" of pulling its forces out entirely -- as it did in Iraq after it failed to work out a Status of Forces Agreement (SOFA) with Baghdad -- is a very real option.
Graeme Smith, a senior analyst at the International Crisis Group in Kabul, says a complete U.S. pullout would be a game changer, given Washington’s vast footprint in Afghanistan.
"The U.S. presence is tremendously entrenched in all spheres of life in Afghanistan," Smith says. "So much of life in this country hinges on this question of whether or not there will be U.S. forces after 2014."
The zero option, if it comes to that, would exacerbate the already formidable security, financial, and regional challenges facing the Afghan government:
The United States would not keep a residual force in Afghanistan to train, advise, and assist the Afghan National Security Forces, nor would it maintain a counterterrorism force there to pursue remnants of Al-Qaeda. Likewise, NATO would not keep a training mission, as that is dependent on Afghanistan and the United States reaching a security deal.
The absence of any Western forces would deprive Afghanistan's nascent security forces of much-needed assistance with logistics, air support, and intelligence.
A complete pullout would also likely see Kabul receiving much less of the $4 billion in annual military aid pledged by foreign donors to sustain the Afghan army and police.
David Young, a civilian adviser to NATO in eastern Afghanistan and an adjunct fellow at the American Security Project in Washington, says the "zero option" would fundamentally change the whole military state of play.
"No troops means fewer people to monitor how Western military financial support is spent, which, in my eyes, translates to less financial support," Young says. "So then, with morale sunk, attrition will be even higher, costing security forces even more money that isn't coming in. While Afghan forces can continue a stalemate with the Taliban without constant U.S. supervision, I don't think they can continue it without adequate funding."
A complete withdrawal of U.S. troops could also translate into much less of the $4 billion in annual civilian aid pledged by foreign donors reaching Afghanistan.
Smith says that could prove disastrous for the many Afghan industries and the economy as a whole, which is heavily dependent on foreign funding.
"Just the sheer amount of money that's going to be pulled out has the potential to be a fundamentally disruptive thing," Smith says. "There would be an abrupt deflation of that war bubble in the economy."
Waning international aid could compound the ominous economic conditions in the country. With most foreign forces leaving, many Afghan businesses have already closed shop and their owners have left the country, taking much-needed cash with them.
One sector of the economy that has already been hit is real estate. The housing bubble, fueled largely by the war economy, has already burst, with prices in the capital slashed by about half in the past three years.
Businesses Tied To U.S. Military
The financial effects of a U.S. withdrawal could be compounded by the absence of the U.S. military, which is a key employer of Afghan civilians and contributes significantly to the Afghan economy.
Many lucrative businesses have been propped up by military spending.
The logistics and construction sectors profit most. The U.S. military hires Afghan companies to transport supplies, equipment, food, water, and fuel to and from U.S. military bases from ports in Pakistan. Afghans have also been employed to build bases, including constructing watchtowers and other facilities.
Afghan companies have also been paid to produce supplies for the U.S. military. As an example, several large bottle factories have sprung up to provide U.S. personnel with bottled water.
The international presence has also allowed a new civil society to take root in Afghanistan.
Scores of women's groups, political movements, and organizations dedicated to upholding human rights and press freedoms and fighting corruption have emerged in the past 12 years.
Young says that without a U.S. military presence and accompanying financial support, many civil society organizations would be unable to work effectively, if at all.
"Without Western troops there won't be a safety net for international donors, which means less nonmilitary aid coming in," Young says. "There would be less support for improving political institutions, government accountability, women's access to resources, and countless other vital needs."
Similarly, many foreign nongovernmental organizations, which rely on protection provided by the international military presence to work, could halt their operations.
In anticipation of the scheduled drawdown, many such groups have already either left or cut their staff numbers to include only essential personnel. A complete withdrawal could deter even the most hardened NGOs from reevaluating such moves.
A complete withdrawal of U.S. troops after 2014 could have a destabilizing effect across Afghanistan's borders but might also be welcomed by powers eager to expand their regional influence.
Central Asian neighbors have already beefed up border security to stop the infiltration of militants, and also of drugs, from Afghanistan. Concern over those issues can be expected to rise with U.S. forces removed from the equation.
But as Smith suggests, the "zero option" may be welcomed by other countries in the region.
"U.S. troop withdrawals in the western provinces of Afghanistan may be welcomed by Iran, and could encourage Tehran's cooperation with the central government in Kabul," Smith says. "Similarly, some authorities in Pakistan are eager to see the Americans leave. On the whole, however, the neighborhood around Afghanistan is watching the situation with some concern."