(Corrects Nov 11 story to clarify Stearns' position at Rift Valley Institute, 5th paragraph)
* Kabila 'riding high' after defeat of M23 rebels, analyst says
* Rumours that president will change constitution to seek third term
* More active international helped defeat M23
* Huge obstacles remain to bring peace to Congo's lawless east
By Pete Jones
KINSHASA, Nov 11 The defeat of Democratic Republic of Congo's most important rebel group has strengthened President Joseph Kabila's grip on political power, but bringing peace to his vast central African nation remains a remote prospect.
"Thank you, Kabila," sang thousands of women dressed in white who marched through the centre of the sprawling riverside capital Kinshasa last week, celebrating the army offensive that routed the M23 rebels in Congo's distant east.
A peace deal to be signed on Monday in Entebbe, Uganda, aims to draw a line under the 20-month rebellion, the most serious conflict in Congo since a major war ended in 2003.
It caps a dramatic turnaround for the 42-year-old president, whose reputation was in tatters just a year ago, accused by the opposition of rigging a 2011 election and humiliated by M23's capture of Goma, the largest city in eastern Congo.
"It is historic. It's hard to exaggerate this moment," said Jason Stearns, project director at the Rift Valley Institute. "This is the first time this Congolese army has defeated a serious armed group militarily ... Kabila is riding high."
The boost to Kabila's reputation comes amid speculation he may change the constitution to run for a third term in 2016. Last month he announced the formation of a national unity government, pulling apart the fragmented opposition.
Some now hope the defeat of M23 could be a first step toward ending two decades of conflict in eastern Congo fuelled by ethnic tensions and rivalry for control of rich deposits of gold, cassiterite and coltan, in which millions of people died.
Kabila has overhauled the command structure of the notoriously ill-disciplined army since Goma, the capital of North Kivu province, fell to M23 a year ago.
The rebel occupation of the city of 1 million people also shocked Western powers into taking a more active role in Congo, turning the tide of the conflict.
The United Nations deployed a new 3,000-strong Intervention Brigade with a mandate to hunt down armed groups, in a break from normal peacekeeping. Its South African Rooivalk attack helicopters played a role in taking M23's hilltop strongholds.
Crucially, concerted diplomatic pressure ensured Rwanda - which has repeatedly backed Tutsi-led rebellions in eastern Congo - did not support M23 as government troops advanced, potentially removing a key factor in long-term unrest.
"The M23 defeat could be an opportunity to begin breaking cycles of fighting and instability in the Kivus once and for all," said Sophia Pickles, campaigner at Global Witness.
The reassertion of a semblance of state authority in the east was welcomed by international mining companies in Katanga province, home of Congo's Copper Belt, 1,600 kilometres (1,000 miles) southeast of Kinshasa.
"The end of the war brings more confidence in the regime," said Denis Kampeshi, mining manager at Australian miner Tiger Resources' giant Kipoi project. "It gives us great reassurance because Tiger has ambitions not just in Katanga but elsewhere in Congo."
Congo's $18 billion economy is on track to become one of the fastest growing in the world, thanks partly to greater political stability. The IMF forecasts it will grow by 10.5 percent next year, driven by mining, which makes up 15 percent of GDP.
Peace in the east could help tap its vast unused potential.
According to some estimates, Congo has up to 80 percent of the world's copper reserves, yet last year it ranked only as the eighth-largest producer, exporting 600,000 tons.
Many are sceptical, however, that Congo has the capacity to impose order outside areas like Kinshasa and Katanga.
Since independence from Belgium in 1960, the country's vast size and poor infrastructure have made it almost impossible to govern. There are just 2,000 km of paved road in a nation the size of Western Europe, and no route from Kinshasa to the east.
"Congo isn't really a country. It's lines drawn on a map," said Martyn Davies, CEO of Johannesburg-based Frontier Advisory consultancy. "It's one of the world's top two or three failed states."
A 19,600-strong U.N. peacekeeping mission is attempting to fill the void left by the Congolese state in the east, where an alphabet-soup of armed groups compete over land, politics, ethnicity and minerals. There are more than 40 armed groups in the Kivus alone, meaning M23's defeat will not end lawlessness there.
M23 is just the latest incarnation of Tutsi frustration in eastern Congo. It took up arms last year saying Congo broke a 2009 deal ending a previous Tutsi uprising against Kinshasa, which it accused of backing the FDLR Hutu militants.
Some FDLR members took part in Rwanda's 1994 genocide in which 800,000 Tutsi and moderate Hutus were killed. The group wants to topple Rwanda's Tutsi President Paul Kagame, and Kigali has used its presence in Congo as a pretext for intervention.
Analysts say a U.N. commitment to hunt down the FDLR, which funds itself with illegal mining and logging, was key to securing Rwanda's neutrality in the recent fighting, but should it fail to do so, Kigali could again intervene.
Kabila, who has been accused of backing the FDLR to counteract Rwandan influence in Congo, has struck a conciliatory tone, pledging to neutralise the group and tackle the roots of conflict, including reform of the army - sullied by rights abuses and corruption.
"M23's defeat was just the first step towards peace," said Stearns. "The army now needs to move against other armed groups, and the government must strengthen state authority in the east."
Some say that M23, with its foreign backers and military discipline, was actually the easiest armed group to tackle. With no support from Rwanda, hundreds of M23 fighters simply retreated across the border into Uganda with their leaders.
M23's political leadership was also willing to make peace because of promises of an amnesty, though this is unlikely to extend to its military leader Sultani Makenga. With the United Nations ruling out a pardon for anyone accused of war crimes, Mai Mai militia leaders have no such incentive to lay down arms.
"The outlook for the same sort of victories against other groups is less positive," said Christoph Wille of Control Risks, noting Mai Mai groups had deeper local roots and preferred guerrilla warfare to conventional battles, unlike M23.
'CONSTITUTIONAL COUP D'ETAT'
In Kinshasa, political tensions are set to rise ahead of the 2016 presidential elections. The constitution limits presidents to two five-year mandates, and rumours of Kabila's hopes for a third term have divided the political class.
Albert Moleka, spokesman for opposition party UPDS, said Kabila may be emboldened by the military victory to crush opposition groups that remain outside the unity government.
"It risks reinforcing Kabila's regime in its tendency to further suppress the opposition," he told Reuters, adding that the new government would remove checks on the president's power.
"I think of it as a constitutional coup d'etat," he said.
On the streets of Kinshasa, opinion is divided. Pacifique Massangue said Kabila deserved a third mandate after attempting national reconciliation and defeating the rebels.
Billboards have sprung up around the city of 8 million people praising the army and Kabila's efforts to heal the nation, which has been racked by conflict since his father Laurent toppled strong man Mobuto Sese Sekou in 1997, ending his 32-year rule.
Student Kevin Yakossou said Kabila should step aside in 2016 before himself becoming an African 'Big Man'.
"He has to leave power. He cannot say that he has defeated M23 and for that continue with another mandate," Yakossou said. (Additional reporting by Daniel Flynn; Editing by Daniel Flynn and Will Waterman)