Afghan presidential candidate Abdul Rashid Dostum climbs on top of a horse and waves at throngs of supporters at a campaign rally in a Kabul stadium Oct. 6, 2004. (Associated Press/David Guttenfelder)

Afghan President Ashraf Ghani likes to say that he has the world’s most difficult job, and no one doubts that he is at least in the running. But amid the plethora of problems he faces, it might come as a surprise that his first vice president, whom he selected, is one of the biggest.

Then again, Abdurrashid Dostum’s name is synonymous with volatility and brutality. For decades, the former plumber, wrestler and oil refinery worker has led northern Afghanistan’s ethnic Uzbeks, first as a ruthless — and reckless — militia commander, now as a politician. The U.S. State Department, in cables released by WikiLeaks, once called Dostum a “quintessential warlord,” and Ghani himself termed him a “known killer.”

That didn’t stop Ghani from making a deal with him. In the last presidential election, Dostum promised and delivered to Ghani the crucial Uzbek vote, propelling the unlikely duo to a narrow victory. But what was convenient a year ago is now quite the opposite. Instead of helping Ghani unite the country, Dostum has revived a sense of indignation toward Afghanistan’s ethnic Pashtun majority and cobbled together an insurrection in the multiethnic north.

Ghani and Dostum’s fragile compact began to unravel when the vice president was accused last December of ordering an elderly political rival to be manhandled and sodomized with a Kalashnikov. It was the second time he had been charged with a similar offense. After the first instance in 2008, Dostum went into a long exile at his lavish home in Turkey. Since refusing to cooperate with the attorney general in May, he has been out of Afghanistan, mostly in Turkey again.

Dostum claims the charges are a form of blackmail, aimed at stripping him of his authority. His followers contend that Ghani used Dostum for votes and is consolidating power into a cabal of ethnic Pashtuns. They say the government neglects and even encourages the deterioration of security in the minority-dominated areas in the north where the Taliban and the Islamic State’s regional affiliate have wrested control of numerous districts and launched a string of suicide bombings and kidnappings.

Last month, Dostum attempted to fly from Turkey to the northern city of Mazar-e Sharif, but the government prevented the plane from landing once it learned who might be on board. At a meeting of Dostum’s followers in late July, two of his closest aides expressed hope that he would return any day, probably by barging across a nearby land border with either Uzbekistan or Turkmenistan. His return, they said, would mark the beginning of a massive wave of protests.

Dostum’s co-conspirators call themselves the Coalition for the Salvation of Afghanistan. They have not always been friendly with each other. Foremost among them is Tajik warlord-turned-provincial-governor Attah Mohammed Noor — against whom Dostum fought vicious battles in the early 1990s. They are joined by Mohammad Mohaqiq, an ethnic Hazara leader and deputy to the government’s chief executive, and Foreign Minister Salahuddin Rabbani, a member of Noor’s Jamaat-e-
Islami party. Together they claim to represent Afghanistan’s three largest ethnic minorities, although the depth of their support among the public, let alone within their own parties, is yet to be put to the test.

They insist that they are not calling for the collapse of the government, only that Ghani relinquish power to officials and cabinet ministers hailing from various parties and ethnicities, Dostum prime among them. A key demand is that the criminal case against Dostum be dropped and his return to Afghanistan expedited. Their rhetoric is menacing.

“We see this as a tyrant government,” Noor said in an interview at his opulent office in Mazar-e Sharif. He said that the coalition is negotiating with the government but that if coalition members aren’t heeded, that could change. “We may have to take control of administrative buildings and airports to put pressure on and paralyze the government,” he said.

Noor took aim at the U.S. government, too, which coalition supporters see as taking Ghani’s side in what should be an internal political dispute.

“We were the ones, not Ghani, who helped the U.S. fight the Taliban,” he said. “It is wrong that the U.S. should use us when they need us and then throw us away like empty Pepsi cans. They shouldn’t support a group of five individuals against everyone else,” he added, referring to an earlier claim that all government decision-making is channeled through Ghani and four others, all Pashtuns.

The allegations of unscrupulousness fly both ways. Ghani’s office has been dismissive of the coalition, saying that its members’ outrage stems not from any illiberalism on his part but from the fact that his firm stance on eliminating corruption has cut off strongmen such as Noor and Dostum from systems of patronage. Ghani, a Western-educated former World Bank employee who gave up U.S. citizenship to run for president, has emphasized transparency as a way of shoring up Afghanistan’s corruption-riddled institutions.

“For the first time, powerful people feel that their wrongdoings will be accounted for through a proper apolitical, independent judiciary — and they feel threatened,” said Haroon Chakhansuri, a deputy chief of staff in Ghani’s office.

The rift risks exacerbating ethnic polarization, especially with coalition leaders claiming that Ghani is brazenly limiting power, not just to Pashtuns, but also to a small group of confidants from his clan — and all under the nose of American advisers who espouse inclusive governance.

On the other side, the lack of any major Pashtun leader in the coalition has made Pashtuns in the north uneasy about the coalition’s intentions.

“This coalition is nothing but a coalition of killers,” said M.W. Matin, a doctor in Mazar-e Sharif who plans to run for office in next year’s parliamentary elections. “But the tragedy is that Ghani had to bring a killer like Dostum into his office just to win.”

For some Uzbeks, Dostum’s violent past is a source of pride. They believe him when he claims to be descended from an ancient line of Uzbek emperors. His face looks out from dozens of giant billboards over Mazar-e Sharif’s drab grid of streets.

“We say that Ghani has a ‘money bank’ but Dostum has a ‘people bank,’ ” said Sher Aqah Tataroghla, a 23-year-old student living in a hostel that is mostly Uzbek. “In the past we couldn’t even speak Uzbek in public, but now you’ll see it on signs around the city. One hundred percent of us are behind him.”

Tajiks in Noor’s party and Hazaras in Mohaqiq’s do not seem to be uniting behind the coalition as uniformly as Uzbeks. Those leaders command more limited cachet in their communities, with followings that pale in intensity compared with Dostum’s. Stoking that sense of ethnic solidarity — mobilized through voting blocs as well as people in the streets — may well be the crux of the coalition’s ultimate strength. Without it, many Afghans may find it difficult to see its leaders as fighting for anything but themselves.

“It’s not for salvation as they say, it is about their money and their pride — that’s how politicians are all over the world, right?” said Moqaddas Rahim, 28, who has been unemployed for four years after serving as an interpreter for U.S. forces. He knows how to use a computer and speaks six languages, including fluent English with a distinctly southern twang.

“To be a good Afghan, you can’t trust your government,” he said. “Look, I’m hopeless, man — not about my God but about my country. Here, the worst criminals become the most powerful people.”

Sayed Salahuddin contributed to this report.