04/01/2014 10:45 am ET Updated Jun 01, 2014

20 Years Ago, Genocide in Rwanda

On April 6, 1994, the president of Rwanda was killed when his plane was shot down as it prepared to land in Kigali, the capital of this tiny central African country of 8 million people. Over the next hundred days some 200,000 Rwandans killed over 500,000 others, typically by slashing them to death with machetes.

The Rwanda genocide may seem like a black hole in history from which no light can ever escape, a unique event forever beyond human understanding. But historical events can be meaningfully explained and the Rwanda genocide is no exception. Like the Holocaust and other genocides, it is a story of identity gone wild.

Unlike larger African countries, whose borders are the aftermath of European colonialism, Rwanda was a nation prior to colonization. Although a distinction was made between Hutu and Tutsi, these were neither tribes nor ethnic groups. Rather, the distinction between Hutu and Tutsi was a fluid one, based on a combination of ancestry and socioeconomic status, including the ownership of cattle.

Rwanda was a single society in which Hutu and Tutsi lived among each other, spoke the same language, shared religious beliefs and intermarried. The Tutsi, comprising 15 percent of the population, were politically and economically dominant. Nevertheless, some Hutu attained some degree of power and economic success, and many Tutsi were as poor and marginalized as the majority of Hutu.

From the 1890s to the early 1960s, Germany and then Belgium reinforced Tutsi power as a means of controlling the country. Identity cards that distinguished Hutu from Tutsi became mandatory, thus requiring everyone to be categorized and making these categories official.

Rwanda became independent in the early 1960s with its Hutu majority, for the first time, in control. Many Hutu saw their attainment of power as a democratic victory after centuries of illegitimate domination by the Tutsi minority. Many Tutsi, rejecting this reversal of fortune, aimed to regain what they saw as their rightful authority.

With identity on everyone's mind, efforts to eliminate official identity cards were unsuccessful.

By the early 1990s, the pressure to be Hutu or Tutsi above all else was intensifying. Many Rwandans saw being Rwandan as more fundamental than being Hutu or Tutsi. Many defined themselves in part on the basis of religious commitments, political ideologies, professional activities, family relations or other identity considerations. But identities other than Hutu and Tutsi became increasingly difficult to maintain.

Two factors drove the dichotomization of Rwandans into what were deemed primordial Hutu and Tutsi categories. One was the threat from a Tutsi-dominated army of Rwandan exiles that was making incursions from Uganda. The other was the rise of a political movement that called itself Hutu Power, which defined Rwanda as a Hutu nation.

Hutu Power denounced the Tutsi as aliens descended from Ethiopian immigrants who had seized Rwanda centuries before and then collaborated with the European colonizers. Ultimately, they came to see Tutsi as "cockroaches" to be eliminated.

Although there were moderates among both Hutu and Tutsi, extremists on each side undermined the claims of moderates on the other. Moderate Hutu who advocated among their fellow Hutu a vision of Rwanda for all Rwandans were undermined by Tutsi extremists who advocated a return to Tutsi rule. The Tutsi extremists seemingly confirmed the claims of Hutu extremists about what Tutsi really wanted.

Correspondingly, moderate Tutsi who advocated among their fellow Tutsi an inclusive and democratic Rwanda were undermined by the Hutu Power position that the Hutu were the true Rwandan nation. Hutu Power confirmed the claims of Tutsi extremists that the Hutu vision of Rwanda left no place for Tutsi.

It remains unclear who shot down the president's plane. Regardless, Hutu Power was ready to initiate genocide. In the first few days, thousands of moderate Hutu who accepted Tutsi as part of the Rwandan nation were killed for betraying their Hutu identity.

By the time the 100-day genocide ended, at least half a million Tutsi had been killed. Many of them were identified, often at the point of a machete, by their mandatory identity cards.