To Sen. Richard Lugar, America's continued military presence in the remote and mountainous nation of Afghanistan comes down to arithmetic.
The Indiana Republican argues that, with Osama bin Laden finally dispatched to a watery grave and his al-Qaida terrorist organization largely evicted from the territory, Afghanistan "does not carry a strategic value that justifies 100,000 American troops and a $100 billion per year cost, especially given current fiscal restraints."
Lugar, ranking member of the Senate Foreign Relations Committee, is far from alone in his assessment. More voices now are calling for America to end its near-decade long involvement in Afghanistan amid claims that continued presence contributes little to the nation's security.
But others, like Sen. John Kerry, D-Mass., chairman of the Senate Foreign Relations Committee, express wariness about withdrawing too soon.
"Now, with the death of bin Laden, some people will ask why we don't pack up and leave Afghanistan. We can't do that," Kerry said, adding that U.S. military experts anticipate insurgents will stage a significant counterattack this spring.
The U.S. military campaign in Afghanistan, dubbed Operation Enduring Freedom, was a response to the terrorist attacks of Sept. 11, 2001, which killed nearly 3,000 at the World Trade Center, the Pentagon and a rural Pennsylvania field. At the time, al-Qaida leader bin Laden was operating out of Afghanistan under protection of the Taliban, an Islamic militia group that ruled the country. U.S. forces quickly overran the Taliban, but have faced an insurgency ever since.
Today, some 98,000 U.S. troops are in Afghanistan, triple the number since President Barack Obama took office in 2009. Last year, he announced plans to begin withdrawing troops beginning this July. The administration is in the process of determining whether to pull out a significant number or a relative few. It also is negotiating with the Afghan government to determine U.S. troop presence after 2014, when the full handover of security responsibilities is set to occur.
Threats in Afghanistan have been superseded elsewhere, according to at least one government official. Michael Leiter, director of the government's National Counterterrorism Center, in February told the House Homeland Security Committee that an al-Qaida terrorist cell in Yemen had surpassed bin Laden's group on the list of organizations considered most likely to attack the U.S.
"I actually consider al-Qaida in the Arabian Peninsula ... probably the most significant risk to the U.S. homeland," Leiter said.
With bin Laden's demise, critics are pushing for an accelerated withdrawal. The Congressional Progressive Caucus sent Obama a letter this week urging him to move quickly.
"Our nation's economic and national security interests are not served by a policy of open-ended war in Afghanistan," that letter said. "A significant redeployment of U.S. troops from Afghanistan beginning in July 2011 will send a clear signal that the United States does not seek a permanent presence in Afghanistan."
Richard N. Haass, president of the Council on Foreign Relations in Washington, D.C., adds that "at the macro or global level, Afghanistan is simply absorbing more economic, military, human, diplomatic, and political resources of every sort than it warrants.''
The Pentagon puts the cost of the war at $119.4 billion for the current fiscal year. Haass said the current rate of spending on the war "is unjustifiable given the budget crisis we face and the need for military, especially air and naval, modernization."
Supporters of a continued strong presence in Afghanistan, however, raise other concerns. The Afghan government under Hamid Karzai remains relatively weak. A quick U.S. withdrawal could create a vacuum that al-Qaida and the Taliban could exploit.
"Simply put, we have had a potentially effective strategy for a rather short time,'' said Ronald E. Neumann, U.S. ambassador to Afghanistan from 2005 to 2007. "… One can say that the trajectory of the policy is working, if not its desired pace.''
Right now, U.S. forces have secured some areas of southern Afghanistan; the goal is to transfer control to Afghan security forces. A smooth transition within the next year would increase the strategy's credibility, Neumann said.
"If nothing important or difficult has been transferred a year from now, the strategy will have to be questioned, perhaps to the point of giving up,'' he said. "These forthcoming operations should have much more focus than the debate over immediate withdrawal numbers.''
The U.S. needs a continuing commitment to fight terrorism, said Anthony H. Cordesman, a national security analyst at the Center for Strategic & International Studies, a Washington
With the raid on bin Laden, "it will take weeks -- and possibly months -- before we can understand just how much we have gained in strategic terms in the war in Afghanistan and our deeply troubled relations with Pakistan,'' Cordesman said. "It will take at least that long to determine how successful al-Qaida will be in finding some form of revenge."
Neumann said bin Laden's death isn't reason enough to dramatically change current U.S. strategy there.
"Insurgent-secured territory in Afghanistan could easily become a new sanctuary area for terrorist operations directed against the U.S. Al-Qaida ... will be under pressure to show its strength through action in Afghanistan and against the United States, Neumann said.
"We turned our back on al-Qaida before. To make the same mistake…to count victory before it is in hand would be exceptionally costly.''