One year ago, I found myself fleeing a firefight out in the eastern deserts of Chad with Khaled Hosseini, author of The Kite Runner. Mr. Hosseini and I had traveled by World Food Program planes and Toyota truck for several days to meet with Darfur refugees who had found shelter in remote desert camps run by the U.N. High Commission for Refugees just across the Sudanese border.
One day, rebels backed by the Sudanese regime in Khartoum attacked a camp we were in, and we had to run for our lives. The firefight left two combatants dead; a Chadian gendarme jumped into the car I was in, bleeding from the chest.
I was glad to get back to Baltimore alive, but I still feel enormous shame that I left thousands of innocent women and children in the dust.
These same rebels recently invaded Chad's capital of N'djamena, and but for the French would have upended the government of President Idriss Deby. But why is the government so fragile? The ugly truth is that Mr. Deby, like too many African leaders, rests his authority on ethnic rivalries rather than building a more representative democracy to reduce ethnic tensions. The result is violent conflict and camps teeming with refugees and the internally displaced.
Few Americans understand that Chad's president is from the Zagawa tribe, which holds power despite being vastly outnumbered by other ethnic groups in the country, such as the Gorane and even the Arabs. Members of such groups have been sending recruits to the anti-government rebels and will tell you they are sick of the lack of representation and uneven divvying up of wealth.
Newly rich from oil, Chad could well afford new roads and schools if the state wanted to provide them. Instead, Mr. Deby's government, ignoring its critics, sinks vast reserves into newfangled weaponry, including planes. The ragtag group of 2,000 rebels on pickup trucks, the ones I fled a year ago, still get support from Khartoum. But what is notable is their ability to rock a government with little more than aging assault weapons and rocket-propelled grenades. The last time they marched on N'djamena, in 2006, the citizens - about 180 ethnicities in all - applauded.
The same governing fault lines led to the recent mess in Kenya. President Mwai Kibaki is a member of a powerful minority group, the Kikuyu. Seventy-eight percent of the country hails from other tribes. When Mr. Kibaki announced that he - and by inference, the Kikuyu - had won re-election, his challenger, Raila Odinga, was ready. Mr. Odinga, a Luo, has attracted political support from others who feel disenfranchised.
While Mr. Odinga publicly called for calm, the torches, machetes and AK-47s came out. While the Western media breathlessly reported on the vengeance killings against the president's tribe, they apparently hadn't noticed the raw venom and ethnic chauvinism espoused by both candidates and their surrogates before and after the election. This vitriol, delivered in local languages to crowds and passed from person to person and family to family, prepared Kenya for bloodletting just as surely as Rwanda's RTLM radio station prepared Hutu extremists to commit genocide in 1994.
The irony is that ordinary Africans in these countries have lived side by side with other ethnicities for generations. In Chad, as in Kenya and Sudan's Darfur province, intermarriage is common, as are mixed communities. But leaders continue to fuel their authority with ethnic bigotry and narrow patronage, setting the stage for chaos.
U.N. peacekeeping missions and even the intervention of former Secretary-General Kofi Annan cannot solve this problem. The underlying cause is systems that create all-powerful presidents and weak parliaments, establishing "winner take all" outcomes that stoke mutual recrimination.
The international community has a key role to play, providing such things as support for the rule of law and peacekeeping. But in the long term, Africa's civil society leaders must train and promote politicians who are up to the basic challenge of ruling multiethnic societies in a globalized world. It is Africans who must press for fundamental constitutional changes to create more democratic systems of checks and balances.
When that day comes, the continent will feed fewer tragic stories to the wire services - and more mouths.
Nancy Langer is director of external relations at the Henry L. Stimson Center, a think tank in Washington. A Baltimore native, she lives in Baltimore County. Her e-mail is firstname.lastname@example.org.