Facing Taliban threats and approaching winter snows, Afghan election officials must scramble to organize a runoff presidential election Nov. 7 after a grim President Hamid Karzai bowed to intense U.S. pressure and acknowledged Oct. 20 that he fell short of a majority.

Afghan President Hamid Karzai during a news conference in Kabul on Oct. 20 AP PHOTO

U.N. Secretary General Ban Ki-moon said it will be a "huge challenge" to pull off new balloting without repeating the widespread fraud that caused U.N.-backed investigators to strip Karzai of nearly a third of his votes from the Aug. 20 first-round election.

Although Karzai's capitulation was a relief to American officials and averted a constitutional crisis, new balloting carries with it the risk of low turnout or another round of wholesale ballot-stuffing and voter intimidation. Another failed election would bring the Obama administration no closer to its goal of a credible, legitimate Afghan government necessary to win public support in the United States for the war and reverse the Taliban's rise.

If the election goes relatively well, it's unclear that a second-round win by Karzai, widely considered the favorite over former Foreign Minister Abdullah Abdullah, would erase the stain brought on his leadership by widespread fraud in the first balloting.

Karzai, standing alongside U.S. Sen. John Kerry and U.N. mission chief Kai Eide, said he welcomed the runoff. He called the decision to hold a second round "legitimate, legal and according to the constitution of Afghanistan."

But Karzai did not express regret over massive fraud — most of it on his behalf.