WASHINGTON—The catastrophe that has befallen Kenya since the rigged election of Dec. 27—killings and displacements, curtailed freedoms, a promising economy on the verge of being wrecked—confirms for the umpteenth time that local politicians, not the remnants of imperialism or ancestral customs, are the major culprits of sub-Saharan Africa’s misery.

In recent years, Kenyans had made an effort to move toward a functioning democracy, a more open economy and a stable institutional environment. The rest of the world responded positively: From Asia to Europe, Kenya was praised as East Africa’s “commercial and financial hub” and was conspicuously absent from the list of troubled nations customarily cited by Africa observers. To top it all, Western democracies claimed Kenya’s government was a bulwark against Islamic fundamentalists in neighboring Somalia.

All of that is now in tatters because President Mwai Kibaki refused to relinquish power after an election that, according to local and foreign observers, was thoroughly rigged in his favor. Kibaki’s decision to cling to power has stoked up tribal, regional and even religious resentments, replacing institutions with violence as a means of allocating power, wealth and prestige. More than 1,000 people have been killed, many more have been mutilated or raped, and a quarter of a million have been made homeless. These numbers are expected to worsen, given the failure of international efforts to mediate between Kibaki and opposition leader Raila Odinga.

Make no mistake about it. The stealing of the election did not create problems where there were none. The dominant tribe, the Kikuyu, was already looked upon with suspicion by other tribes, including Odinga’s Luos, who felt marginalized. Muslims felt left behind by Christians. Various provinces resented the concentration of power in the Central Province and the capital, Nairobi. But these tensions and grievances were only latent because, since the end of one-party rule in 2002, various institutional mechanisms seemed to be gradually falling into place, promising gradual participation, mobility and decentralization. Kibaki’s worst crime is to have pulverized the expectation that peaceful means could redress old injustices.

Government security agents are not the only ones doing the killing, however. By most accounts, the opposition is closely linked to various gangs that have terrorized Kikuyus in the Rift Valley and other areas of western Kenya. And there are signs that groups not linked to the political fight have seized the opportunity to settle scores too. Once the government opened the Pandora’s box, anything could come out. And it has.

Kenya emerged from its struggle for independence in the 1960s as a corrupt one-party state under Jomo Kenyatta. Daniel arap Moi prolonged that state of affairs after 1978. Under these rulers, Kenya became—to use the words of George Ayittey in the recent book Making Poor Nations Rich—a “vampire state.” But then Kenya opted for a transition that seemed to set it apart from much of the continent. Now when it looked as if Kenya was leaving behind its authoritarian politics, Kibaki, with a single stroke, has managed to make Kenya look no different than most corrupt and violent African states.

In doing so, the Kenyan ruler has followed the worst tradition of African politics of the last half-century. After the trauma of colonialism, one African leader after another chose to establish tyrannical kleptocracies rather than the rule of law, cloaking their actions in foreign ideologies instead of building on local customs that held some promise for the development of limited governments and vibrant economies. Not surprisingly, between 1975 and 2000, sub-Saharan Africa’s per capita gross domestic product shrank on average by 1 percent, while countries in other continents prospered. South Korea, whose per capita income was similar to that of Ghana in the 1950s, became a success story while the African nation stagnated. For each Botswana—the only success story in Africa for many years—there were dozens of failures.

Only in recent years did a substantial number of African nations start to change their political economies by shedding the ideological fallacies and brutal practices that squandered the continent’s independence. Kenya seemed to be one of them, making a significant contribution to a region that has been growing at around 6 percent a year and attracting significant foreign capital. Kibaki’s decision to wreck all of that is truly a crime against all Africans.