NAIROBI (Reuters) - Shortly after Congo President Joseph Kabila came to power in 2001, the U.S. embassy in Kinshasa sent cables to Washington exuding quiet confidence in the 29-year-old who had replaced his recently assassinated father, Laurent.
In one, released later by Wikileaks, the ambassador described an articulate but shy man, seemingly weighed down by the burdens of leading Democratic Republic of Congo. Days later, Kabila spoke on television for the first time.
"Kabila's address is encouraging, reflecting a shift toward the reform and moderate elements in the Congolese power structure,” the ambassador wrote.
Fifteen years later, with an election due but Kabila showing little sign of being ready to relinquish power, an incident at Kinshasa's airport highlighted how much has changed.
Tom Perriello, the U.S. envoy to Africa's Great Lakes region, was accosted on the tarmac by several angry, finger-wagging Kabila supporters, including a member of parliament. One of the men shouted, "Be careful of the Congolese. We no longer need you!"
For years one of Kabila's firmest backers, Washington is now driving international efforts to prevent any bid to extend his time in power when his second term runs out in December.
Last month, the U.S. government imposed further sanctions on Congolese security officials after dozens of people protesting against election delays were killed in Kinshasa.
"At this point it, is clear the government has not been willing to move towards an open or participatory democratic election," Roger Meece, a former U.S. ambassador to Congo who also ran the U.N. peacekeeping mission there, told Reuters.
"Private discussions are not working so you get to the point where public comment is the only way forward. The tools are pretty limited but we should be doing more with sanctions and specific actions."
U.S. determination to see Kabila stand aside is rooted in a constitutional ban on him seeking another term. But the unprecedented intensity of the pressure stems from changes in both the United States and Congo.
For years, many in Washington saw Kabila as Congo's best bet.
His 2006 election win against ex-rebel Jean-Pierre Bemba was credible, despite the street battles that followed. A 2011 election was widely criticized but Washington held its nose and recognized Kabila as winner over Etienne Tshisekedi, a veteran opposition leader whose fervent popularity at home is often matched by deep distrust among Kinshasa-based diplomats.
"American policymakers appear to have concluded that accepting Kabila, although ignoring democracy promotion, was the wiser course," Anthony Gambino, a former head of USAID in Congo, wrote in 2012 for African Futures, a digital forum.
"It is not at all clear that accepting the fraudulent outcome leads to longer term stability."
Coming from the Swahili-speaking east, Kabila has always been seen as an outsider in mainly Lingala-speaking Kinshasa, surrounded by political and family groups competing for access and influence.
Augustin Katumba Mwanke, one of his closest advisors, juggled these networks for years. But after he died in a plane crash in 2012, advisors multiplied and diplomats say it has become harder to decipher Kabila's plans.
Many of those in Kabila's close circle now appear mainly preoccupied with holding on to power, rather than ruling in a coherent way, some diplomats say.
As a result, issues have often been handled clumsily. For example, in 2015, security forces broke up a press conference organized by a small band of pro-democracy activists and partly sponsored by the U.S. government. A U.S. diplomat was caught in the swoop, angering Washington.
Accusations of U.S. interference have become increasingly common from the Kabila camp.
"We don't need people throwing oil on the fire to try to blow up Congo," Jean Thierry Monsenepwo, head of a pro-Kabila youth organization and one of Perriello's airport critics, said to the cameras. "That is why we told this man that he is not welcome in this country."
Kabila's drift toward authoritarianism has also splintered his ruling alliance, the most significant loss being Moise Katumbi, the millionaire former governor of the mining province Katanga. In him, the opposition has someone with deep pockets and a favorable reputation in Washington.
The tough U.S. line is also an attempt to arrest a broader trend of regional leaders clinging power, after heads of state in Republic of Congo, Rwanda and Burundi tweaked or sidestepped laws to extend their mandates.
Crucially, Congo has caught the attention of a number of senior U.S. officials, many of whom are becoming increasingly open about their frustrations over Kabila.
Senators of both major U.S. political parties have worked together on sanctions legislation. The creation of a special envoy post has seen administration officials with high level support jet in and take a more robust approach than when they relied solely on resident diplomats.
The U.S. Department of Justice also announced results of a long investigation that exposed how a U.S. hedge fund funneled $100 million in bribes to top Congolese officials in return for access to mining concessions.
In the case, the first U.S. foreign bribery case against a hedge fund, a subsidiary of Och-Ziff Capital Management Group pleaded guilty in federal court in Brooklyn last week to participating in a scheme to bribe Congolese officials. Och-Ziff will pay $412 million to resolve U.S. probes into its actions there and in other African countries.
With commodities prices low, U.S. businesses are less interested in Congo than they have been in the past. Phoenix-based Freeport-McMoRan Inc agreed earlier this year to sell its stake in Congo's Tenke Fungurume copper and cobalt mine, part of efforts to cut its debt load. That means there are no longer any major U.S. economic interests in the country.
But Washington provides more than $400 million in aid every year to Congo on top of $300 million for the U.N. peacekeeping mission, bringing it clout. U.S. diplomacy has been active in the region, especially cracking down on Rwanda for backing rebels in eastern Congo.
For now, the U.S. position toward Kabila is far more hard-line than Western and African counterparts. Europe has ratcheted up rhetoric against Kabila but not yet found a common position on sanctions.
Jason Stearns, a Congo expert, said there was a reluctance in Europe to follow such an aggressive approach but the mechanics of pushing sanctions through the bloc were also a factor in EU foot-dragging.
In previous crises, Kabila has also been able to rely on the support of regional African powers such as Angola and South Africa for diplomatic and military support. So far, leaders have stressed the need for calm without stating a clear position.
Stearns questioned how much regional countries will appreciate Washington throwing its weight about on their patch. Meanwhile, emboldened by U.S. policy, Congo’s opposition is threatening further protests unless Kabila stands aside.
"People are growing more worried and lowering their expectations for what might be possible in terms of an orderly change of government there," a U.S. Congressional staffer told Reuters, asking not to be identified. "In Congo, we are trying to avert a worst-case scenario."
(Corrects identification of Kabila supporter quoted in paragraph 20.)
additional reporting by Patricia Zengerle in Washington; editing by Peter Graff