NAIROBI, Kenya -- The letter was as bold as it was explosive. Signed by the South Sudanese president and sent out with a news release, it chastised its powerful recipients for collectively stealing $4 billion from the world’s newest country, before it was even born.

"We fought for freedom, justice and equality. Many of our friends died to achieve these objectives. Yet, once we got to power, we forgot what we fought for and began to enrich ourselves at the expense of our people," the letter read. At least 75 officials were served with copies, which offered amnesty for the partial return of funds.

That letter set off a firestorm in the media and added to the steady stream of bad publicity that South Sudan had received in its first year of existence.

Yet its origins tell of a much deeper story, one in which America’s newest friend in Africa has turned out to be far less friendly than hoped, and international efforts to create a reliable democracy in an unstable region are faltering badly.

The author of the letter detailing South Sudan’s corruption wasn’t a South Sudanese but an Ethiopian-American who previously had been an advocate for South Sudan in Washington and had very recently taken a job with the United Nations. Ted Dagne also had been appointed by South Sudanese President Salva Kiir as a special adviser.

Because of his anti-corruption work, Dagne was forced to flee South Sudan for his safety soon after the letter was released, and for now he isn’t allowed back into the country. The United Nations says Dagne remains on contract with its mission in South Sudan.

"He’s obviously very affected, very distraught," said a friend who requested anonymity in order to speak freely. "I don’t know what kind of impact this is going to have. He was obviously very influential in Washington."

U.S. officials declined to comment on the record or to officially condemn the incident. The South Sudanese minister of information, Barnaba Marial Benjamin, wouldn’t discuss Dagne and his role in the corruption letter. Kiir’s press secretary, Chaat Paul, also declined to discuss Dagne.

Dagne, who worked for 22 years at the Congressional Research Service as an African specialist, was part of a tight-knit group of U.S. officials with close ties to the southern Sudan rebel group, the Sudan People’s Liberation Movement.

Advocates in Washington call Dagne the movement’s point man in Congress. He traveled frequently with the late Democratic New Jersey U.S. Rep. Donald Payne to Africa, where they often met with the southern Sudanese rebels. Dagne was known to play a personal voice mail from John Garang, the movement’s founder, to visitors.

His efforts and those of other American officials who were pro-Sudan People’s Liberation Movement paid off in a 2005 peace deal that led last year to an independent South Sudan. But Garang died six months after signing the peace accord, and Kiir took over as a consensus replacement. Unlike Garang, who had a Ph.D. from Iowa State University, Kiir had little education and had been a guerrilla fighter his entire life.

This January, Dagne left Washington and moved to Juba, South Sudan’s capital, on a U.N. contract to advise Kiir directly and work on curbing a plague within the nascent government that even friends of the Sudan People’s Liberation Movement realized could prove fatal to their cause: a free-for-all looting of South Sudan’s oil revenue by the movement’s officials.