In “Darfur Now,” Theodore Braun’s absorbing documentary about the atrocities in Darfur, the westernmost region of Sudan, Don Cheadle poses a fundamental question facing moviegoers attending a film about African strife: How do you respond to an event as difficult to understand as a government-sponsored mass murder of part of a country’s civilian population?

The United Nations has estimated that by 2007, 200,000 people had been killed and 2.5 million displaced from their rural villages in Darfur. Recalling his first visit to a refugee camp two years ago, Mr. Cheadle says his initial reaction was a wave of hopelessness.

Since then, however, the actor, who first became aware of the crisis while making the 2004 movie “Hotel Rwanda,” has found his activist voice and written (with John Prendergast) a book, “Not on Our Watch: The Mission to End Genocide in Darfur and Beyond.” In the documentary he is shown with a group that includes George Clooney on a mission to Egypt, which has close ties with Sudan.

Mr. Cheadle asks us to consider the children caught in the crisis. “You sense their potential,” he says. “You see that kids really are just kids. You think, maybe their journey is in some way tied into my journey on this planet. That’s you and that’s me.”

Luis Moreno-Ocampo, the chief prosecutor of the International Criminal Court in The Hague, is an equally eloquent commentator on the question of how to respond, and on the need for the same kind of planetary consciousness that surrounds the issue of global warming. “Most people care about family and neighborhood but not about the world,” he laments.

But Mr. Moreno-Ocampo, who grew up in Argentina during the military dictatorship when thousands were tortured and “disappeared,” saw how everything changed when the generals were prosecuted for mass murder. He sees the situation in Sudan as analogous: “It’s a bureaucracy committing crimes by public servants.” He admits that the movement for justice and the prosecution of those responsible has proceeded at a frustratingly slow pace. But eventually, he says, “the truth will prevail.”

Mr. Cheadle, using his celebrity, and Mr. Moreno-Ocampo, wielding the limited power of the court, which the Sudan government does not recognize, are two of the more than half a dozen voices in the film, which examines the situation from multiple perspectives. What “Darfur Now” offers is a collective vision of actions, small and large, taken on many fronts, to end the crisis. The movie is a quiet, methodical call to action.

Its activist stance and its cautiously hopeful view come at some sacrifice, however. Although the roots of the Darfur killings, which the American government has labeled genocide, are examined, they are not thoroughly analyzed.

The role of China, Sudan’s largest trading partner, which imports 60 percent of Sudan’s oil, is touched on, but its implications are barely mentioned. A movie can instantly humanize an international crisis by showing the faces of the suffering. But it can’t impart the hard information and background with the efficiency of a written text.

“Darfur Now” is also wary of showing the savagery. Tearful tribespeople, uprooted from their villages and living in sprawling refugee camps where food is scarce, tell of rapes and killings. Some corpses are shown along with the charred remains of villages, but the horrors inflicted by the government-sponsored, Arab-speaking militias known as the Janjaweed are not shown.

In the movie, the official voice of the Sudanese government belongs to Abdalmahmood Abdalhaleem Mohamad, Sudan’s ambassador to the United Nations, who scoffs at the notion of a genocidal campaign against the people of Darfur. The conflict is an internal matter, he insists, and has to do with the apportioning of scarce resources. Sudan has refused to comply with the International Criminal Court’s recent arrest warrants for Ahmad Harun, Sudan’s minister of the interior, and Ali Kushayb, a leader of the Janjaweed militias, for crimes against humanity.

In the meantime, progress inches along on several fronts. Adam Sterling, a University of Southern California student, works tirelessly to get a bill passed that will force California to divest from companies that benefit Sudan, and with much fanfare, Gov. Arnold Schwarzenegger signs it. Pablo Recalde, an Ecuadorian, established a program that transports food by convoy to the starving people in West Darfur. It is dangerous work, because the convoys are frequently attacked.

Hejewa Adam, a mother whose village was destroyed by Janjaweed militias, joins rebel forces and wields a gun. “I’ve learned to fight,” she says. “It’s very natural. It’s like drinking water.”

The scenes of this ragtag rebel army training in the hills suggest it has a long way to go before becoming a force to be reckoned with. But at least it exists.

“Darfur Now” is rated PG (Parental caution suggested) for thematic material involving crimes against humanity.

DARFUR NOW

Opens today in New York and Los Angeles.

Written and directed by Theodore Braun; director of photography, Kirsten Johnson; edited by Edgar Burcksen and Leonard Feinstein; music by Graeme Revell; produced by Cathy Schulman, Don Cheadle and Mark Jonathan Harris; released by Warner Independent Pictures and Participant Productions. Running time: 99 minutes.