In the next few weeks, Barack Obama will make a decision that will define his presidency. Will he escalate the war in Afghanistan, sending 40,000 additional US soldiers to reinforce the 68,000 already there to engage in an open-ended, nation-building counterinsurgency mission? Or will he redefine US objectives and ask his advisers to craft an alternative strategy? Two events intended to bolster the case for the former–Afghanistan’s August 20 presidential election and Gen. Stanley McChrystal’s August 30 assessment of the war–have instead demonstrated the wisdom of the latter. Perhaps more crucial, the events have raised opposition to and uncertainty about escalation from leaders across the foreign policy and national security establishment, creating a rare opportunity for the administration to shift course and save face.

Opponents of escalation now include conservative columnist George Will, who editorialized in favor of withdrawal in the September 1 Washington Post, as well as Senators Richard Durbin, Russ Feingold and Carl Levin, chair of the Armed Services Committee. Meanwhile, Senators Dianne Feinstein, Jack Reed and John Kerry, chair of the Foreign Relations Committee, have weighed in with pointed skepticism about the cost and terms of escalation. Kerry, in a September 27 Wall Street Journal op-ed, called for a “fuller debate about what constitutes success in Afghanistan,” citing former Secretary of State Colin Powell’s mantra, What’s the exit strategy? For his part, Powell has reportedly warned the president of the need for a clearly defined military mission. And another career military man, Army chief of staff George Casey, has reportedly expressed concern about the drain on military resources.

Afghanistan’s recent election revealed the fraud, corruption and unpopularity of the US-backed regime. But it is McChrystal’s report that raises the gravest doubts. Although it maintains that “success is still achievable,” the daunting challenges it identifies should lead foreign policy realists to conclude the exact opposite. Among the obstacles it cites are: “the weakness of state institutions,” “widespread corruption and abuse of power,” a “crisis of confidence among Afghans,” the growing influence of insurgent groups backed by narcotrafficking and/or the Pakistani government, and the operational culture of foreign forces there, which poorly understand Afghan social, political, economic and cultural affairs. McChrystal plans to integrate US troops into Afghan units. With this strategy, he concludes, it “is realistic to expect that Afghan and coalition casualties will increase.”

Are Americans willing to pay that price? What is the goal of a counterinsurgency mission? How will “victory” be measured? These are the questions that should dominate the debate. There are, of course, many other moral, political and strategic reasons to oppose escalation, including the hundreds of billions it could cost. And there are plans for withdrawal that would shift US involvement to regional diplomacy and development, targeted counterterrorism and intelligence sharing, such as one offered by William Polk on page 11 and the exit strategy proposed by Representative Jim McGovern, which has garnered ninety-eight supporters in the House. For now, however, the administration should be pushed hard to explain the purpose and logic of increasing US involvement. Until it does, any escalation has failed the very test Obama established: “absolute clarity about what the strategy is going to be.”