When the United States first suggested that all options would be considered when it came to a long-term security agreement with Afghanistan -- including leaving no U.S. forces on the ground after 2014 -- it was seen as bluster.
But as talks drag on, the "zero option" is beginning to look increasingly realistic.
This month a large gathering of tribal and civil leaders known as a loya jirga will be held in Afghanistan to decide on a draft security deal struck by Washington and Kabul in October.
But significant disagreements remain on the Bilateral Security Agreement (BSA) and accompanying Status of Forces Agreement (SOFA), including Washington's demand that its troops be granted immunity from prosecution under Afghan law.
Afghan President Hamid Karzai is expected to abide by the loya jirga's ruling, but there are several reasons to believe the United States might not be in the mood for further negotiations.
Support in the United States for the Afghan war, which is now in its 12th year and has left more than 2,150 U.S. troops dead and nearly 20,000 wounded, is at its lowest point.
According to a Washington Post-ABC News poll conducted in July, about three in four Americans think the war is no longer worth fighting. And for the first time, more than half of poll respondents said the war had failed to contribute to U.S. national security.
Mounting tensions between Karzai and U.S. officials, a bloody offensive this year by the Taliban, and the failure to start peace talks with the Taliban have all convinced the U.S. public that the country needs to cut its losses.
David Young, a civilian adviser to NATO in eastern Afghanistan and an adjunct fellow at the American Security Project in Washington, says convincing the U.S. public of the need for continued military engagement beyond 2014 will be a tough sell.
"If the Afghan economy and Afghan security forces can't stay afloat on their own now, then another five years or 10 years certainly won't be able to do it -- that's the rationale," Young says. "We've pumped everything we can into this situation and into this country, and if this doesn't do it then nothing will."
The growing unpopularity of the Afghan war largely stems from financial concerns in the United States.
The U.S. economy is struggling to climb out of a global financial downturn, and U.S. taxpayers are wary of adding to the trillions of dollars that have already been spent on the military campaign and in propping up the Afghan economy.
Graeme Smith, a senior analyst at the International Crisis Group in Kabul, says Afghanistan is playing a risky game by delaying its decision on a security agreement with Washington.
Smith says there is a misconception in Afghanistan that the United States needs Afghanistan more than Afghanistan needs the United States. But if tempted, he says, Washington could pounce on the opportunity to cut its losses.
"These days in Washington, the mention of Afghanistan makes people sigh deeply," Smith says. "There is profound donor fatigue. Afghans don't realize how much the West would love an excuse to pull out and walk away. It would save billions of dollars a year for America at a time when America is hurting for cash."
Remote intelligence, surveillance, and strike capabilities have come a long way since the U.S.-led invasion of Afghanistan in 2001. These remote capabilities can be employed from U.S. bases in the Persian Gulf and even the U.S. mainland. Quite simply, drones have altered conventional thinking on how counterterrorism operations can be carried out.
In Afghanistan and neighboring Pakistan, drone attacks have been a largely successful, albeit controversial, tool in weakening Al-Qaeda and other extremist groups fighting the United States and Afghan security forces in Afghanistan.
Smith says that if the United States opts for the "zero option" it could rely on drones to protect its core interests, including making sure Afghanistan does not again become a base for Al-Qaeda.
"If push came to shove, America could pursue some limited counterterrorism in parts of Afghanistan by treating Afghanistan like North and South Waziristan [tribal agencies] in Pakistan, or parts of Yemen, or parts of Somalia," Smith says.
New Foreign-Policy Priorities
When it comes to Afghanistan, U.S. President Barack Obama's comments in recent years have often related to troop withdrawals and a long-term U.S.-Afghan security agreement. When it comes to foreign policy, events in Egypt, Syria, and Iran appear to have taken priority.
Young says that the United States' reasons for entering the Afghan theater are fading in the minds of Americans.
"If and when another attack on American interests outside of Afghanistan originates from Afghanistan, it would be back on the front burner," Young says. "The sense is that the only time Americans are affected by Afghanistan is when they are in Afghanistan. That has been the general sense in the public for the last few years. The longer that perception pervades, the less relevant Afghanistan feels to Americans."