The Obama administration now fears that the Afghan election may not produce a clear winner until next spring, which officials said could throw President Obamas policies into flux by leaving Afghanistan without a credible leader for months. The prospect of a runoff election is growing after President Hamid Karzai was awarded 54.6 percent of the votes in the much disputed presidential election last month. But even as American officials noted that the Afghan authorities had begun printing ballots for a second round of voting, these officials said they were worried that a runoff could not be held before Afghanistans fierce winter starts in November. Such a long delay could deepen Mr. Obamas troubles in Afghanistan, at a time of deteriorating security there and mounting skepticism in Washington about whether the United States should deploy more troops to try to stabilize the country. For the White House, a winter of political uncertainty in Afghanistan may be the worst of all possible situations, officials and outside experts said. There is already vocal disenchantment with the war, across the country and among Democrats in Congress. We are well aware that we have 12 to 18 months to start to show progress, said a senior administration official, who asked not to be identified in order to freely discuss internal policy. The clock starts to run out after that. Mr. Karzais final vote tally was significantly smaller than administration officials expected, even if he needs to clear only 50 percent to avoid a runoff. But accusations of ballot-stuffing and other fraud have led election authorities to order an examination of ballot boxes in 10 percent of polling places. If some votes are invalidated, that could push him below the 50 percent threshold. While the United States has warned Mr. Karzai not to declare victory before the ballot investigation is complete, administration officials acknowledge that he remains the most likely winner. His main competitor, Abdullah Abdullah, a former foreign minister, finished a distant second, with 27.8 percent of the vote. Administration officials expressed surprise that Afghan authorities were laying the groundwork for a second round of voting, even before the investigation of the first round had been finished. But the calendar works against holding a runoff before the spring. The countrys brutal weather and forbidding geography would make going to the polls extremely difficult. There is an exquisite dilemma here, said Bruce Riedel, a senior fellow at the Brookings Institution who helped develop the administrations policy. The strategy requires an Afghan government that is credible and legitimate, both to get Afghans to support it and to get Americans and their allies to help. The strategy cant work around a South Vietnamese-style government. A runoff would be preferable to a discredited first-round Karzai victory, Mr. Riedel said. But if the vote is put off until next spring, he said, the administration will have to deal with an interim leadership that will be much less effective in helping with American priorities, like peeling off moderate elements of the Taliban. What is placed on hold is any kind of political reconciliation, of trying to split the Taliban, he said. Its very hard to do that because you need the Afghan government as your partner. The Obama administration had also planned to begin a major new anticorruption drive in Afghanistan, once the dust settled from the elections. That strategy would include assigning more civilians to the American Embassy in Kabul to work with the Afghan government on reforms of the legal system, as well as looking for ways to crack down on the drug smuggling that has fueled the resurgence of the Taliban. None of this was going to be easy to begin with, in part because Mr. Karzai has proved resistant to Western attempts to rein in corruption. Before the election, he struck political deals with Afghans who have been accused of drug smuggling, including his running mate, Marshal Muhammad Qasim Fahim. Administration officials had hoped that in a second term, free of worries about his political future, Mr. Karzai would be more amenable to a Western-style anticorruption campaign or that Mr. Abdullah, if he won, would be more amenable to working with the West to crack down on drug smuggling and corruption. The plan was to hit the ground running right after the elections with the anticorruption work, another senior official said. It is not clear the administration could begin such a campaign as long as the election results remain uncertain. Western officials said the best they might hope for is some kind of political deal, under which Mr. Abdullah could end up working with Mr. Karzai in a prime minister-type role. But that, too, may be too much to hope for, given the enmity between the two men. In the meantime, Afghanistan faces a tense wait, with the risk of an expanding Taliban insurgency that could even take aim at Mr. Karzai or Mr. Abdullah personally, Mr. Riedel said. Elements of Mr. Obamas strategy can continue without a political resolution, he said. The Pentagon can conduct operations against the Taliban and train Afghan forces, while other parts of the Obama administration can assist economic development. But even the basic question of whether to send more American troops has been caught up in uncertainty over the election. At a news conference on Thursday, Defense Secretary Robert M. Gates noted that the administrations original timetable called for assessing the need for more troops after the election results were in. There is no question that the nature of the election in Afghanistan has complicated the picture for us, he said. Still, Mr. Gates said it was proper for the president and his senior advisers to take time to absorb the recently completed assessment of the Afghanistan security situation by the senior commander there, Gen. Stanley A. McChrystal, before deciding. I think, theres been a lot of talk this week and the last two or three weeks about Afghanistan, Mr. Gates said. And frankly, from my standpoint, everybody ought to take a deep breath.