So the actor and director did a self-described tutorial before launching the Eastern Congo Initiative four years ago, a non-profit advocacy group dedicated to peace and prosperity in the region. On Wednesday, he brought his star power and expertise to Washington, meeting with Secretary of State John Kerry and testifying on Capitol Hill.
Affleck, who has made nine trips to Congo, expressed cautious optimism about the outlook for the African nation while imploring lawmakers to remain diligent.
"The accomplishments over the last year were hard fought, but they are fragile and they are reversible," Affleck told the Senate Foreign Relations Committee in a packed hearing room.
He also had lunch with several lawmakers and sat down for interviews along with former Sen. Russell Feingold, the special envoy for the African Great Lakes region and the Democratic Republic of the Congo.
Affleck joked about crashing congressional offices and the likely confusion over an actor slated to play Batman in the sequel to "Man of Steel."
"What are you doing here, aren't you supposed to be wearing a cape?" Affleck said in an interview with The Associated Press, citing a typical comment.
The star and director of last year's best picture "Argo," and star in the upcoming "Gone Girl" said he was taking the celebrity attention and using it to focus on an issue he cares deeply about — the Democratic Republic of the Congo.
"Outside my family and my work, this is it. This is my legacy. This is the thing I will be identified with. I take it extremely seriously," Affleck said in a 20-minute session in which his passion for the subject was evident.
Congo, the former Belgian colony of about 68 million people, is one of the most volatile in Africa. Violence has claimed the lives of 5 million people since a regional war that began in 1997 and displaced hundreds of thousands.
Among the positive steps, Affleck cited the surrender last November of the armed militia M23 and the appointment of Feingold. His Eastern Congo Initiative, with two employees in the U.S. and 12 in the Congo, has had success through its community-based partnerships and, as Affleck noted, capitalism.
Theo, a chocolate company based in Seattle, is getting tons of its cacao beans from eastern Congo. Coffee is next, Affleck said.
"Now we have a window of hope in a place that has had a lot of war, a lot of conflict, a lot of suffering, basically no security sector," Affleck said.
Feingold said elections will be crucial as they stand as a "symbol to the people that they really have something to do with the government."
Affleck praised the work of former President George W. Bush on African issues as well as the effort of Cindy McCain, wife of Sen. John McCain, R-Ariz.
"Our Republican friends have perhaps been better on Africa than my party," said Affleck, a Democrat.
Members of the Senate committee, including Chairman Bob Menendez, D-N.J., and John McCain, praised Affleck's commitment. Although the actor said he was "no Congo expert," the senators said he was imminently qualified to testify.
Affleck urged Congress to provide the funds for personnel and resources for the special envoy's office and to pressure President Barack Obama to engage directly with President Joseph Kabila, among other steps.
Affleck, in the interview, said his fame gave him a "special spotlight" while acknowledging the "certain skepticism about actors, about entertainment advocates." The key, he said, is to "demonstrate that you know what you're talking about, that you're not a dilettante."