The United States may be looking to keep 20,000 U.S. troops in Afghanistan beyond the 2014 timeline for withdrawal, as negotiations began in Kabul Thursday over the continued presence of American forces. A number of thorny issues, including immunity from prosecution for U.S. military personnel, are among the current obstacles to a new agreement over the number and role of U.S. forces after the removal of most foreign combat troops over the next two years.

Though no official word has yet been given on that number, it is believed the United States is hoping to retain a force of 20,000 to train and support Afghan security forces and go after extremist groups, including al-Qaeda, the Associated Press reported Thursday. Earlier this week, Secretary of Defense Leon Panetta said the administration expected a decision in the next few weeks on the number of troops to remain, but the conditions governing their presence, including the troublesome immunity issue, could stretch negotiations over a new security agreement out to as long a year, the AP said.

The immunity issue is what prevented the extension the United States sought to the Status of Forces Agreement in Iraq, which called for withdrawal of U.S. forces by the end of last year. The Obama administration wanted to keep a residual force in Iraq beyond the 2011 deadline negotiated between the two countries during the presidency of George W. Bush. Negotiations reached a stalemate, however, when the Baghdad government insisted on the right to prosecute U.S. personnel for crimes committed in their country.

The issue is a particularly sensitive one in Afghanistan, where U.S. Army Staff Sergeant Robert Bales allegedly killed 16 Afghanis in a shooting rampage in two Afghan villages in March of this year. Bales was whisked out of the country after his arrest by the U.S. military and is awaiting trial in the United States, where he faces 16 counts of premeditated murder and six counts of attempted murder. Shortly after the attack, Afghan President Hamid Karzai said he wanted U.S. troops out of the country by 2013, a year ahead of the agreed upon deadline for withdrawal. That demand has apparently been dropped, but the Afghan government has said it would not accept a provision in the new bilateral security agreement that would ban prosecution of U.S. troops in Afghan courts.

Testifying before the Senate Armed Services Committee Thursday, Marine General Joseph Dunford, President Obama’s choice to succeed General John Allen as International Security Assistance Force commander in Afghanistan, described the immunity clause as an essential part of any new agreement. “I think we would need full [legal] protection for those in uniform,” Gen. Dunford said. “I think we’d also need to have appropriate protection for those civilians from our government that are working over there.”

In September, the United States withdrew the 33,000 additional troops sent to Afghanistan during the “surge” of 2010, leaving about 66,000 U.S. military personnel still in the country. The pace of the withdrawal over the next two years and the number of forces to remain beyond 2014 were issues that arose during the committee hearing. John McCain, the committee’s senior Republican, said his understanding from talks with military commanders in Afghanistan is that the current troop level is needed to complete the mission by the 2014 deadline. “And if we start a, quote, ‘steady pace’ withdrawal that we will not be able to accomplish a lot of those missions there,” McCain said. “If we can’t accomplish the mission, I’m not sure why we should stay,” the Arizona Republican said, adding, “I think we need to look at other options.”

The United States as well, as its coalition partners, need to provide “some level of assistance” to the Afghan National Security Forces for the ANSF to be successful in counterterrorism operations “post-2014,” Dunford told the committee. Sen. Lindsey Graham (R-S.C.) tried to pin the general down on the number of U.S. troops needed. Could the task of training and equipping the Afghan forces be accomplished “with a fraction of the troops we have today?” Graham asked.

“Absolutely,” the general replied, though he would not say how large or small a fraction it might be. When Graham asked if the number needed would be less than the 28,000 U.S. troops in Korea, Dunford said, “I believe that’s the case, Senator.” Asked if more than a thousand would be needed, the general said, “I do not believe a thousand would be enough.”

“I’ll look at the strength of the enemy, I’ll look at the capabilities and capacities of the Afghan National Security Forces, judge the capabilities and capacities of the coalition forces and then make a recommendation on what our force contribution ought to be, between now and 2014 – and then beyond as we go into the ‘decade of transformation,'” Dunford said, indicating some level of forces would be needed until 2024

The war in Afghanistan, already the longest in U.S. history, began with the U.S. and NATO invasion in the fall of 2001, following the al-Qaeda attacks in New York and Washington on September 11 of that year. Coalition forces overthrew the Taliban government and drove out al-Qaeda forces, with many of them taking refuge in neighboring Pakistan, where al-Qaeda leader Osama bin Laden was killed by U.S. Navy SEALs on May 1, 2011. Elements of the Taliban and other insurgents continue to attack and harass the international forces, however; and “insider” attacks on Western troops by Afghan National Security personnel resulted in suspension of recruitment of new trainees and the curtailment of joint missions in recent months. At least 50 U.S. and NATO troops have been killed by insider attacks this year.

A report on cnsnews.com Thursday pointed out the apparent contradiction between the Obama administration’s plans for a post-2014 military presence in Afghanistan and statements made by Vice President Joe Biden in the debate with Republican vice presidential candidate, Rep. Paul Ryan (R-Wis.) “My friend [Ryan] and the governor [Mitt Romney] say it’s based on conditions, which means it depends,” Biden said in the October 11 debate. “It does not depend for us,” the Vice President insisted. “We are leaving in 2014, period.”

Photo of Afghan President Hamid Karzai: AP Images