Members of President Barack Obama's national security team are calling for an accelerated drawdown of U.S. troops in Afghanistan, according to the lead story in today's New York Times.

American involvement in Afghanistan, initially justified by the imperative of bringing Osama Bin Laden to justice, has spanned a decade. Bin Laden's death has compelled officials to re-evaluate the scope and intent of a costly war that has become America's longest.

Military commanders including Defense Secretary Robert Gates and top Afghanistan commander General David E. Petraeus have argued that a steep reduction in American force levels could endanger fragile security gains, with Gates advocating for the importance of being able to maximize my combat capability. Those espousing this view have the support of Secretary of State Hillary Clinton, who along with Gates was instrumental in urging Obama to commit U.S. forces to Libya. Conditions in Afghanistan, from politicial stability to the capacity of Afghani security forces, would weigh in favor of staying longer, an official quoted in the story said.

But momentum seems to be building for an opposing viewpoint that questions a strategy that makes Afghanistan the central focus of America's campaign against terrorism. Vice President Joseph Biden supports a reduced role for troops in Afghanistan, and a measure to more rapidly transfer responsibility to Afghan security forces narrowly failed the House of Representatives last week, signaling rising discontent from a Congress that is confronting a soaring deficit while the war in Afghanistan consumes an estimated $2 billion a week.

The debate also coincides with an imminent reshaping of Obama's national security team. Gates' tenure is drawing to a close, with current CIA director Leon Panetta his likely successor. Petraeus would then ascend to Panetta's current position leading the CIA, which would put him in charge of an agency that directs the kinds of limited counterterrorism, such as drone strikes, that could gain an increased emphasis as troops depart.

One of Obama's early moves as president was to commit 30,000 additional troops to Afghanistan, a move that generated intense and sometimes fractious debate within his national security team and the State Department. Ryan Lizza detailed these contrasting approaches in an excellent analysis of how Obama's foreign policy has evolved, noting that at the time of the Afghanistan surge decision the president was deferential to his generals.