Austrian filmmaker Hubert Sauper has spent years exploring the heart of darkness: colonialism’s impact on Africa. We Come as Friends completes his observant trilogy. In Kisangani Diary (1998), not released in the United States, he followed ignored Rwanda refugees caught up in a Congolese war. His Oscar-nominated Darwin’s Nightmare (2004) tracked ecological disasters in Tanzania caused by world market pressures.

In 2012, he facetiously emulated the Great Explorers to search for the source of neocolonialism in Sudan just before it split into two separate countries, a boundary that he sees as the epicenter of neocolonial competition between the United States and China, and he can already see that it’s about to lead to more war. He narrates his pointed political travelogue from France to Africa in a manner similar to cinematic essayist Chris Marker, and he borrows a technique from the environmental activists/pranksters the Yes Men with an attention-getting and disarming ruse.

He builds a two-person paper plane, a “flying tin can” he names “Sputnick,” that flies slow and low. It can be a glider when needed and land in any open area. It also proves more reliable than a United Nations helicopter. (Curious, and so thin, kids find the aircraft irresistible.) He also hits on the idea to dress himself and assistant director Barney Broomfield in pilots’ uniforms that are convincing enough to allow them access into otherwise out-of-bound government and corporate facilities, and to get employees to talk frankly in front of the camera.

For historical reference, Sauper flies over Fashoda, along the Nile, where Britain and France clashed in 1898 to the brink of war before dividing up sections of North and East Africa between them. Emphasizing how foreigners are as intent on draining Africa’s resources as ever, Bibles and guns are imported with the same old-fashioned rhetoric of religion and development. One woman missionary’s proclamation, “God is calling Texans to Sudan,” takes on added significance as Sputnik flies by huge oil derricks. In interviews, Sauper says he any reference to Arabs in the film is an indication that other foreigners similarly brought Islam with the Koran. Christian evangelicals are more prominently seen proselytizing, though, as has been filmed in such recent documentaries as God Loves Uganda, though here at least with less homophobia.

The unique and strongest sections are when Sauper infiltrates Chinese projects. It is striking to see how the Chinese oil workers are kept isolated from the local people and culture, even from tasting the local food, let alone that there are no African employees, not even trainees. Tellingly, the air-conditioned workers’ shelters have been built with bulletproof protections.

Building on interest in his plane, including offering rides, Sauper has a disarming knack for getting people to talk: corrupt politicians; a British investor; U.S. ambassador to South Sudan, R. Barrie Walkley, who inaugurates a power plant that will provide more electricity to a gold mine than to a local village; and a U.N. bomb disposal expert. For all the bonhomie on screen, the filmmaking team risked life and limb over the two years of filming, from malaria and parasites, to dead and wounded support crew from a robbery.

With sobering glimpses of bodies from the war that follows, whether blamed on fighting over resources, religion, or ethnic tribal differences, the heart of the film is mother-of-six Celestine, who sings “My Land,” a protest song. Its line, “Our poor politicians/Have denied our rights,” she sadly explains, was enough to get students arrested, beaten, and killed, and forced her into exile in the United States. Sauper leaves a distinctly pessimistic impression about any future for her in her homeland.