Sebastian Junger and Nick Quested ask a lot of the audience for their new documentary “Blood on the Wall” — empathy, critical thinking and understanding.

While the coronavirus pandemic has become the dominant issue for the world, immigration continues to be a political and cultural fulcrum, particularly in the United States regarding its relationship to Mexico and Central American countries and their migrant populations.

President Donald Trump might not be tweeting daily anymore about caravans heading to the United States, but the ongoing fight over who will be counted in this year’s U.S. census shows it is as salient an issue as ever. And for that matter, it has been since the birth of the republic, as people in a nation composed mostly of immigrants debate the meaning of a more perfect union.

So Junger and Quested did what documentarians do: They talked to people, a lot people, on their own turfs, to humanize a topic that is prone to demonizing. That’s a tall task, given how immigration has been tangled up in interrelated issues such as border security, drug trafficking, poverty and electoral politics.

It meant talking to former Mexican President Felipe Calderón and Ludy, a Honduran teenager on her own, heading north in a migrant caravan. It meant speaking to Alan Bersin, a former commissioner of the U.S. Customs and Border Protection, and Santiago, a poppy farmer in Mexico.

“We’re reaching a juncture in this election year when understanding the socio-political landscape of our neighbors is incredibly important for people before going into a voting booth,” Junger said in a statement.

The documentary is the second co-directed by Junger and Quested for National Geographic Documentary Films, following their 2017 “Hell on Earth: The Fall of Syria and the Rise of ISIS.” It comes out Sept. 30 on the National Geographic channel.

The propensity to report from these dangerous locales is not new for them. Junger’s first documentary, co-directed with the late Tim Hetherington, was 2010’s “Restrepo,” which followed for more than year the U.S. Army’s 2nd Battalion of the 503rd Infantry Regiment of the 173rd Airborne Brigade Combat Team in Afghanistan’s Korengal Valley. That movie was a companion to his book “War,” and provided fodder for many of the projects that followed, including a sequel, “Korengal.”

A 2014 interview with CQ Roll Call hints at the approach to such material. “One of the things I wanted to do with ‘Korengal’ is get that conversation going, and if it makes people squirm, good. I mean, if you don’t squirm at that stuff, there’s something missing from you,” Junger said then. “If you start disassembling combat and understand it, yes, it gets very dark. It gets very everything for that matter.”

With “Blood on the Wall,” the approach stays the same.