Afghans learned this week that they have to vote again to choose between two would-be presidents. On the surface, that’s seemingly good news for Washington; both candidates are thought to be anti-Taliban, anti-al-Qaeda, and for a U.S. security deal.

But danger lies in this second round between frontrunner and former Foreign Minister Dr. Abdullah Abdullah and former Finance Minister Dr. Ashraf Ghani Ahmadzai. The revote could expose Afghans to risk from the Taliban, delay a U.S. security deal and possibly make a smaller U.S. footprint or none at all a fait accompli. Worst of all, the second round could pit the two Afghan contenders against each other in an ugly fight that could preclude much needed political cooperation when the election is done—tension evident when both men sat down to talk to The Daily Beast last week.

Each obliquely accused the other’s campaigns of voting fraud in the first round, and neither man indicated a willingness to include the other in a future Afghan administration.

Some seven million Afghan voters already risked the Taliban’s wrath on April 4th, defying the militants by turning out in unexpected droves. The Taliban fired a round of commanders who failed to produce enough bloody attacks that time. The June 21st vote gives them a chance at a do-over.

The second round also keeps U.S. decisions over how many troops to leave in the country after 2014 on hold—while keeping the troops themselves focused on packing up their bases rather than helping Afghans focus on the enemy.

Both candidates have pledged to sign the security pact that outgoing President Hamid Karzai has spurned. But a new Afghan president won’t take office until August, just ahead of the unofficial September drop-dead deadline by which U.S. commanders have to start packing in haste to get out by the end of the year.

This delay comes as the White House grapples with how many troops to leave even if there is a deal. The choices so far: the 10,000 troops that U.S. commander in Afghanistan Gen. Joseph Dunford recommends, allowing him to keep six regional bases open to support the Afghan military as well as U.S. diplomats and intelligence officers; or the 5,000 or less that some in the White House favor, meaning a narrow counterterrorism and advising mission based in and around Kabul.

The later the Afghan decision comes, the smaller the U.S. force will already have shrunk, possibly making the smaller numbers the White House is considering a foregone conclusion.

U.S. officials in Kabul and Washington say the runoff also threatens to inject more bitterness between the two candidates, making it harder for the eventual administration to form stable governments afterwards just as the country is grappling with a drawdown in U.S. troops and international aid.

U.S. officials have said they would welcome working with either candidate—adding that the political “bench” of talented, highly educated Afghans is so narrow that the country needs both. They need the diplomatic and financial skills of Ghani the Pashtun former World Bank official and professor who spent much of his life overseas, whose delicate form, gentle mannerisms and careful academic speech leads some to call him “the Afghan Mahatma Gandhi.” And they need the political and military connections of Abdullah, a former member of the anti-Taliban Northern Alliance who stayed in the country throughout the conflicts with the Soviets and the Taliban, with his deep ties to the Afghan community forged through that wartime experience.

U.S. officials said NATO’s own analysis of the first round of voting points to an even larger Abdullah win in the second round, which could damage Ghani—effectively ending the political career of a man seen as uniquely able to navigate the world of the international aid and economic development needed to keep Afghanistan afloat. The officials spoke on condition of anonymity because they were not authorized to speak publicly.

The NATO voting analysis, obtained by The Daily Beast, shows that of Abdullah’s 45 percent share of the April vote to Ghani’s 31.6 percent, Abdullah won 14 out of the top 20 provinces in terms of voter turnout, and that throughout the country, he won 18 percent of the Pashtun vote—though he has a Pashtun father and Tajik mother, and is most famous for his aforementioned role fighting the Pashtun-majority Taliban.

Ghani would have to win 80 percent of the 1.6 million votes that didn’t go to either man, whereas Abdullah only has to win 22 percent—and he just won the backing of the candidate who came third in the race, Pashtun Zalmai Rassoul, the ex-foreign minister who took 11.5 percent of the vote in the April poll.

In the interview with The Daily Beast, Ghani was undeterred, insisting he will pick up the lion’s share of the votes in the second round. Abdullah was equally convinced he would win.

Neither man indicated a willingness to include the other in their future administration—one sign of that growing bitterness U.S. officials feared when both men sat down in their homes-turned-campaign headquarters for interviews with The Daily Beast. Each accused their opponent in veiled language of voting fraud.

“This time we are going to do everything to ensure both that we have monitors and that we support the presence of third party monitors so fraud can be avoided,” Ghani said, careful in the interview not to slam his opponent by name.

But a day after election officials announced the second round, Ghani got more pointed in a news release: “Regrettably, inflammatory language and threats of violence—where the opposing team promised ‘rivers of blood’—created a chilling environment, in which close to 800,000 votes that should have been declared fraudulent were included in the final count,” he said. “Our documented complaints regarding districts where people had not been able to vote, but boxes had been stuffed, were ignored.”

Abdullah dismissed charges his supporters were threatening violence, saying some of them had simply gotten “emotional” over voting fraud he said was aimed at him.

“It’s been like a systematic shutting off of our share,” Abdullah said. “To begin with, it was a shortage of ballot papers in the areas where there would be more voters,” likely to vote for his campaign.

Abdullah already lost one election to widely-reported voting fraud, to Karzai in 2009. He said he didn’t believe a second round would be any more honest, so he withdrew.

He said this time around, he would use every legal measure available to fight the results if he suspects fraud again—but not violence.

“If we didn’t win because we didn’t have votes, I’ll take it as it is,” he said.

Both men agreed on one thing: the West’s patience and pocketbook is running out, and serious fence mending with international donors is needed.

“Simply put, our national revenue is $2 billion,” Ghani said. “Our security expenditure is $5 billion.” Until the Afghan economy picks up, continued international support is the only way for the country to survive, he said.

Eventually, he said Afghanistan’s mineral wealth and other resources would spell economic independence.

“We are in the heart of Asia,” Ghani said, going into pitch mode hearkening back to his time at the World Bank, when he would build a case for providing aid to a struggling country. “Asia is being transformed into the largest economic continent in the world. Without a stable Afghanistan,” he said, you can’t have a stable Asia.

“Afghanistan’s golden times are behind us when the maximum level of support from the international community was available,” Abdullah said. “So there will be tough times ahead of us,” that he hopes to combat by reassuring international investors that Afghanistan is worth spending more money on.

“The legitimate outcome of the elections will provide an opportunity and the Afghans will come back together once again to help reviving the economy,” and spending their cash—and encouraging the international community to keep doing the same.