The Afghanistan election results were reviewed by the independent Election committee of the United Nations last month, which concluded that the Karzai government rigged the elections by over 30% . Hence Karzai was forced to seek another re-run of the elections, which was scheduled for November first week.
Now the main opposition leader Abdullah Abdullah, has withdrawn from the race , citing fears of massive rigging by Karzai team once again. This might in fact force the UN team there to thoroughly review the election mechanism, and make acceptable changes. That might only mean further delay in Afghanistan elections. This can in turn cause more harm to the American and NATO forces stationed in Afghanistan.