Samuel jabs his finger at the television screen, which is broadcasting images of opposition supporters lobbing tear-gas canisters back at the riot police who fired them. "They say these are ODM supporters. But look, he's a Luo, she's a Luo; that's another one. That one, he could be anything. But these are all Luos, not just 'opposition supporters'."
I stare at the screen, comparing the faces to those of Samuel and his brothers, all of whom are Kikuyus. After 15 years reporting Africa, I can usually distinguish a Dinka from a Maasai, a Tutsi from a Hutu, an Eritrean from a Djiboutian, but I'm struggling here. "How can you tell?" "Luos are stocky, very well-built. They have big jaws. It's just obvious."
It was a conversation that would have been inconceivable a fortnight ago, clunkily tasteless five years ago. Samuel, a talented painter, comes from a section of Kenyan society I have come to know and admire, and on which rests this country's future. Born in a multi-ethnic slum, he has rubbed up against members of the Luo, Kamba, Luhya and Kisii communities all his life. He belongs to a cosmopolitan urban generation that always used to bristle when asked the question "Which tribe are you?", responding defiantly: "Actually, I'm a Kenyan."
Like many of that generation, he voted across tribal lines during the recent elections, choosing the Luo opposition leader Raila Odinga - whose Orange Democratic Movement (ODM) he regarded as a force for change - instead of the Kiku yu incumbent, Mwai Kibaki. Today Samuel, who abandoned his shack when Luos set the neighbourhood aflame, is reassessing some fundamental beliefs. He would never vote that way again. And he will be very, very careful in future to live among his own. "I'm becoming more tribalistic with every passing day."
Those who know Kenya have winced at the international media's portrayal of the crisis as some sort of Rwandan Genocide Mk II, with Luos and Kikuyus pitched against one another in the wake of "tribal voting" that reflected ata vistic hostilities. Kenya's violent explosion was rooted, rather, in cynical governance, the ruthless ambitions of its politicians, the yawning divide between prospectless poor and the smug elite, and the generational exasperation of millions of youngsters chafing at the indifference of a geriatric leadership.
But if the factors are complex, their expression has been horribly crude. And the lynchings, church-torchings and manhunts have triggered an accelerated process of ethnic polarisation - mental and physical - in a country that believed it had reached a level-headed accommodation with its tribal differences. As the atrocities mount up, Kenyans are starting to think of themselves in radically different ways.
Nowhere more so than in the slums. "In my area, the kiosk owners are now asking for people's IDs before they sell you anything," says Joseph, a taxi driver who lives in a largely Kikuyu slum and is himself a Kikuyu. "If you're a Luo, they won't serve you. And everyone is saying no Kikuyu will ever rent premises to a Luo again. The Luos in Kawangware will have to leave and no new ones will be allowed to come in."
But the middle classes also feel they are being forced to choose their camp, having brushed off ethnic sensitivities along with the mud of the upcountry samba (farm). "I went to dinner with colleagues recently and there was silence round the table," says Ruth, a young journalist. "We were so aware of the landmines in the conversation - because it was a mix of ethnic groups - that no one dared say anything."
A kind of reckoning
Even mzungus (westerners) are having to recalibrate, sprouting ethnic antennae they possessed when it came to hot spots like Rwanda, but never seemed necessary in Kenya. "Somehow, we've managed to send a Kikuyu camera crew to Kisumu," one television producer confessed with embarrassment. Stuck in a Luo stronghold, his Kikuyu reporters didn't dare venture out, let alone film. Western employers are chartering planes to scoop up employees whose ethnicity was regarded as irrelevant on appointment, but who are now regarded as being at risk.
"There's been a kind of reckoning with the idea of Kenyan-ness," says Parselelo Kantai, a Kenyan writer. "It was something we'd all been talking about but hadn't got round to. Now people have to make a hard decision about whether it's a viable concept or not."
In Kenya, as in most African states, self-image cannot be disentangled from colonial story. The British imperialists who settled the country did not invent its tribal configuration. Speak to any elderly Kenyan and they will tell you that their gran dparents were keenly aware of differences between Kamba and Kikuyu, Kikuyu and Maasai, with cattle raids and small wars against rivals across the lines peppering village existence.
But historians say that ethnic identity was a surprisingly malleable concept, becoming set in stone only with the colonial state. As white settlers rushed into Kenya in search of land, indigenous people were allocated "tribal reserves" and issued with the kipande, a pass defining their ethnicity. Some of Kenya's ethnic labels today did not exist before the colonial experience - the term "Kalenjin", for example, started being used only in the late 1940s, as a convenient way of grouping the Nandi-speaking peoples.
Acting on the well-established principle of divide and rule, British administrators allotted certain tribes certain functions: Maasais made good soldiers, the farming Kikuyus - deemed money-hungry and too clever by half - were meant to feed the nation, Kambas made for excellent houseboys. Those stereotypes are still in common use today, bandied about among Kenyans as though they capture eternal truths.
Under Kenya's first president, Jomo Kenyatta, a cynical system of presidential patronage reinforced these distinctions. In the top-heavy post-colonial state, prosperity depended on access to State House. Encouraging his fellow Kikuyus to settle outside their usual confines, Kenyatta made clear that those groups which supported the opposition would not be invited to "eat" from the national table, paying for their disloyalty by blocking their way to civil service jobs, private sector contracts and infrastructure. It is no coincidence that Kisumu, Odinga's home town in western Kenya, is today a decaying urban centre, its fish, rice, sugar and cotton industries either stagnating or dead in the water.
As poverty levels soared under Daniel arap Moi, ethnic hostility simmered. Moi, a Kalenjin, capitalised on the suspicions of the smaller tribes, presenting himself as the only leader who could keep the Kikuyus' vaunting ambition in check. You could detect the antagonism in the coded language: politicians railed against "a certain community" (the Kikuyus) or "the people of the lake" (the Luos). But the lid stayed on, thanks to Moi's iron grip. Kenyans of all stripes came to see themselves as brothers in suffering, victims of a sleazy and brutal leader.
When Mwai Kibaki won the 2002 elections at the head of a multi-ethnic coalition, many expected such tensions would dissipate. But the new president threw out the draft of a new constitution trimming his executive powers, sacked his coalition partners and withdrew into an ethnic citadel. While western governments expressed delight at the new administration's economic performance, Kenyans complained that the Kikuyus were at it again. The "Mount Kenya Mafia" - cronies from Kibaki's Kikuyu tribe and its neighbouring Embu and Meru groups - was playing the old patronage game.
Important ministries, critics noted, rested in the hands of "a certain community", with only inconsequential portfolios going outside the ethnic circle. With them went dodgy procurement contracts, local investment and jobs for the boys. "Go to any government department and you will be able to tell the minister's eth nicity by looking at the faces of the staff," one Nairobi-based journalist told me.
The conviction that only Kikuyus and their cousins were "eating" meant Odinga's campaign promise of majimboism - federalism - found a ready audience. The notion sounds uncontroversial to outsiders, but ordinary Kenyans interpreted it very differently. To their ears, maj im boism meant that, in future, only Luos would be allowed to own land in Luo areas, only Kambas would be allowed to run shops in Kambaland.
Raila Odinga was officially declared the loser of the rigged elections, but majimboism is in effect already being practised on the ground. The old kipande, with its ethnic labels, may have gone, but Kenyans can usually pinpoint tribal affiliation on the basis of name alone, spelled out on national identity cards. These are now being demanded at makeshift barricades by young, angry men wielding machetes and clubs. Already, a quarter of a million Kenyans - most of them Kikuyus fleeing Rift Valley homes - have been displaced and made homeless.
"Majimboism is already here in our country," says one Kikuyu kiosk owner, who, like many Kenyans in an increasingly paranoid nation, does not want his name used. "People have learned never to move to an area where you don't belong. Or go there to work but never move your family there. Then, if there is trouble, you can pick up and go. It's good to stay where you belong."
It is too early to say how far this de facto ethnic partition will go, how deeply the scars of the past weeks reach. Working against the trend is urbanisation, which forces tribes to live cheek by jowl, socialising and working with each other, dating and marrying one another. What is undeniable is that ruthless politicians, seeking the most effective issue around which to rally support, in the age of multiparty democracy, have pushed the concept of the nation state to breaking point.
"This crisis is a direct result of Kibaki politics," says Kantai. "Five years ago, no one was talking about Kikuyus or Luos. It just wasn't an issue."
Kenya's ethnic groups
The population is roughly 34 million, made up of more than 40 groups, the largest of which are the Kikuyus, Luhyas, Luos, Kalenjins and Kambas.
Ethnicity has seldom been an issue in Kenyan politics and some group labels such as Kalenjin became common only in the 1940s under British rule.
The largest group, the Kikuyus, makes up 22 per cent of the population. Their traditional home is central Kenya, to the north and west of Nairobi. Mwai Kibaki, the incumbent president, is a Kikuyu.
The opposition leader Raila Odinga is a Luo. Luos and Luhyas together make up 27 per cent of the population; they traditionally come from western Kenya.
Kalenjins, from the Rift Valley district, are the next-largest group. Kibaki's predecessor Daniel arap Moi is a Kalenjin; he was elected with support and opposition from both Luo and Kikuyu politicians.