* Rwanda genocide sowed seeds of recurring ethnic strife
* For years, Congo has paid price in blood for its riches
* Tiny Rwanda has not flinched from invading giant neighbour
* Questions hang over how far M23 rebellion can spread
By Pascal Fletcher
Nov 22 (Reuters) - History seems to repeat itself in Democratic Republic of Congo.
Once again, armed rebels are on the move in the vast central African country's eastern borderlands with Rwanda and Uganda.
This Great Lakes area, where colonial era borders cut at random through ethnic groups, has in the last 20 years been a crucible of conflict and ethnic rivalry that has launched multiple uprisings and invasions, at least one even reaching the Congolese capital Kinshasa 1,000 miles to the west.
The latest Tutsi insurgents, calling themselves M23 and mirroring a previous 2004-2009 revolt, this week easily seized the North Kivu provincial capital of Goma and say they too want to "liberate" Congo and march to Kinshasa.
Whether they can remains to be seen, and Congo government troops were fighting back on Thursday.
The M23 revolt once again focuses the attention of an uncomprehending world on a territory in the heart of Africa the size of Western Europe that has dazzled explorers and invaders for years with its treasure trove of resources: rubber, timber, gold, diamonds, copper, as well as cobalt, uranium and coltan.
Congo has paid in blood and suffering for these natural riches. Abuses under colonial rule in the late 1880s and early 1900s during a rubber boom saw agents and soldiers of Belgian King Leopold II sever human hands, feet and heads to force natives to extract the white latex from the luxuriant forest.
Independence from Belgium in 1960 turned Congo into a Cold War battleground fought over by rebels and mercenaries, CIA agents and Cuban guerrillas and also led to the long crippling kleptocracy of U.S.-backed dictator Mobutu Sese Seku.
The last two decades have only worsened Congo's "Heart of Darkness" image - propagated by Joseph Conrad's brooding 1902 novel - with conflicts that at one stage sucked in the armies of six African countries, spawned a plethora of armed groups and created a deadly maelstrom of war, hunger and disease.
Estimates from humanitarian agencies say over five million people have died in this destructive vortex since 1998 alone.
"The Congo is a story of ... a country where the state has been eroded over centuries and where once the fighting began, each community seemed to have its own militia, fighting brutal insurgencies and counterinsurgencies with each other," wrote analyst and author Jason Stearns in his 2011 book on the Congolese war, "Dancing in the Glory of Monsters".
He compared Congo's recent turmoil to "seventeenth-century Europe and the Thirty Years' War", a religious and political conflict in which foraging armies devastated entire regions.
The roots of eastern Congo's most recent cycle of violence can be found in the 1994 genocide in neighbouring Rwanda, when the world largely stood by as soldiers and militia of the Hutu ethnic group killed 800,000 Tutsis and moderate Hutus, in a bloodletting that ripped apart the country's tribal faultlines.
This brought on the coming years of chaos, as Tutsi rebels led by Paul Kagame, now Rwanda's president, toppled the Hutu government and sent the perpetrators of the genocide fleeing into eastern Congo along with two million Hutu refugees.
Since then, the presence of Hutu 'genocidaires' in eastern Congo, grouped in the enduring Democratic Forces for the Liberation of Rwanda (FDLR), has given Kinshasa's small but militarily powerful neighbour an excuse to interfere and invade.
One such Rwandan intervention ended Mobutu's corrupt reign in 1997, replacing him with longtime eastern rebel Laurent Kabila. Kabila's falling out with his former Rwandan and Ugandan backers in 1998 led to another eastern rebellion, by Congolese Tutsis supported by Rwandan and Ugandan forces.
Troops from Angola, Namibia and Zimbabwe backed Kabila in a multinational conflict lasting until 2003. Dubbed Africa's first "World War", it included widespread plunder of Congo's minerals. Kabila was assassinated in 2001 and succeeded by his son, Joseph, the current Congolese president re-elected last year.
In 2004, a Congolese Tutsi warlord, General Laurent Nkunda began a fresh rebellion among the ethnic Rwandan Tutsis in eastern Congo, to counter what he said was their persecution by Kabila's army working with the FDLR.
Once again, Congo's government accused neighbouring Rwanda of being behind the Nkunda insurgency, which ended in a 2009 peace accord with Kabila. But Tutsi rebellion has resurfaced again in the M23, whose leaders say the agreement was not honoured by Kinshasa.
Rwanda denied backing Nkunda - it later arrested him - and has even more vehemently rejected charges this year by Congo and a panel of United Nations experts that it is supporting, supplying and directing the current M23 insurgency.
However, few abroad believe the public Rwandan denials, especially since Kagame has been on the record for years as saying that Rwanda will defend itself from any neighbouring threat. In this, he includes the FDLR in eastern Congo, still active though depleted in numbers from previous years.
"We will never shy away from crossing our borders to prevent a repeat of what happened in 1994 (the Rwandan genocide)," he told Reuters in a 2000 interview.
Congo says Rwanda also benefits from minerals such as tin, tungsten, tantalum and gold mined in its east and smuggled out over the border, and U.N. experts have accused at least one M23 leader, Bosco Ntaganda, of being involved in such trafficking.
For more than a decade, the United Nations has kept one of its largest peacekeeping forces in the world - 17,000 strong - in the Congo, and this MONUSCO force faces criticism for failing to stop the M23 rebels taking Goma this week.
But despite the historical precedents, some analysts do not see the M23 with either the capacity or intention to march on Kinshasa, although Goma's fall was an embarrassment for Kabila and could encourage other opposition challenges to his rule.
"We do not expect a major escalation by M23 (and backer Rwanda) beyond its provincial stronghold of North Kivu," Eurasia Group's Africa Director Philippe de Pontet said.
He described the territory's significance for Rwanda as "a security buffer for Tutsis on both sides of the border and as a revenue source, largely from so-called conflict minerals."
With uncertainty surrounding the future course of the M23 rebellion, the words of "Mad Mike" Hoare, who fought in the Congo in the 1960s and became the epitome of the white mercenary in Africa seem appropriate to the case: "Anything can happen in the Congo and frequently does".