A 2001 photo by Stanley Greene of a Chechen mother who had lost her child. (Stanley Greene/Noor)

Stanley Greene, a onetime Black Panther who became a celebrated international photojournalist, portraying war, poverty and disaster in Chechnya, Afghanistan, Iraq and the U.S. Gulf Coast after Hurricane Katrina, died May 19 at a Paris hospital. He was 68.

He had complications from hepatitis, which led to liver cancer, said a friend and colleague, Kadir van Lohuizen.

In his youth, Mr. Greene dabbled in radical politics and spent time in a psychiatric hospital before becoming an assistant to the acclaimed photojournalist W. Eugene Smith in the early 1970s.

Mr. Greene chronicled the punk rock scene in San Francisco in the 1970s and early 1980s before moving to Paris, where he worked as a fashion photographer.

“I was a dilettante,” he told Newsweek in 2004, “sitting in cafes, taking pictures of girls and doing heroin.”

The outline of a body, removed after a snowfall. Chechnya, 1995. (Stanley Greene/Noor)

His career in photojournalism began as “an accident” at age 40, he said, when he was on assignment in East Berlin late in 1989, at the very moment the Berlin Wall was breached. His photograph of a young woman in a tutu atop the wall was reprinted all over the world. She was above the scrawled phrase “Kisses to All,” waving a bottle of champagne as guards descended on her.

Inspired by the example of Smith, Robert Capa and other photojournalists, Mr. Greene discovered his vocation.

“I honestly believe photography is 75 chance and 25 percent skill,” he said in a 2012 talk in Charlottesville “In accidents, we really discover the magic of photography.”

He kicked his drug habit and traveled the world, a striking figure in his black leather jacket and sunglasses, accented with scarves, rings, bracelets and a bandoleer of film canisters across his chest.

“He was very charismatic,” van Lohuizen said in an interview. “People would melt for him because there was integrity in his eyes.”

[Poet. Follower of light. Storyteller. A remembrance of photographer Stanley Greene.]

Over the years, Mr. Greene took his cameras to Croatia, Kashmir, Afghanistan and Lebanon. He covered genocide in Rwanda and strife in Azerbaijan, Iraq and Syria.

Stanley Greene. (Sarah Shatz)

In Mali in the early 1990s, he saw children dying of starvation as flies crawled across their faces.

“I photographed them as I would a fashion model,” Mr. Greene later wrote.

He was unhappy with the results, “but they taught me a lesson,” he told Newsweek in 2004. “You have to take photographs from the heart and not from the head.”

His assignments often put him in danger. In 1993, he was the only Western journalist inside the Russian parliament building when it came under siege during a violent coup attempt that left almost 200 people dead.

“The fact that I thought I was going to die gave me courage,” Mr. Greene told the New York Times photography blog Lens in 2010. “Courage is control of fear. I think that this incident is the one that steeled me.”

He traveled more than 20 times to Chechnya, where he chronicled the devastation wrought by Russian troops as they battled separatists in the former Soviet republic.

“There are stories that get to you so deeply that you have to get them out — and this was mine,” Mr. Greene told the Times.

His 2003 book, “Open Wound: Chechnya 1994 to 2003,” containing 81 photographs and an accompanying text, was “a testament to the fact that photography’s moral force is alive and well,” Toronto Star foreign correspondent Olivia Ward wrote in 2004.

Mr. Greene was one of the few Western journalists in Fallujah, Iraq, in 2004, when four U.S. contractors were killed. Their bodies were burned and then hung from a bridge.

“We need to see it because it’s reality,” he told the Times. “If we can’t stomach watching our men and women being killed in these situations, then we shouldn’t send them there to be killed in such gruesome ways. We can’t have it both ways.”

Shortly after Hurricane Katrina flooded New Orleans and the Gulf Coast in 2005, Mr. Greene was there to photograph the physical and psychic damage. He returned for the next five years, showing how the lives of thousands of people had been forever changed.

As a photographer, Mr. Greene was a classicist of the old school: He preferred working in film, using Leica and Nikon cameras, and he detested the digital ma­nipu­la­tion of images. His composition techniques were drawn from his earlier study of painting.

But as a journalist who entered war zones and photographed the destitute and dying, Mr. Greene said he didn’t pretend to have impartial neutrality in photographing his subjects.

“I have been accused of having lost my objectivity,” he told Newsweek. “But when you sit on a fence and watch genocide without doing anything about it, you are as guilty as those who are committing it.”

Stanley Norman Greene Jr. was born Feb. 14, 1949, in Brooklyn. Both of his parents were actors and social activists. His father, who was blacklisted for his political beliefs in the 1950s, had roles in the films “For Love of Ivy” and “The Wiz.”

The younger Mr. Greene “was that kid my parents told me to stay away from,” he said in 2008. He participated in antiwar demonstrations and joined the Black Panthers, later sheepishly admitting, “I was attracted to the Panthers by the berets and leather jackets.”

Because of drug and behavioral problems, he spent two years in a psychiatric facility in his teens.

In the early 1970s, he became an assistant to Smith, whose photographic essays in Life magazine and other publications are considered landmarks of the form.

Mr. Greene later moved to San Francisco, where he studied painting at the San Francisco Art Institute, receiving a master’s degree in 1980. While there, he photographed the city’s thriving music scene and its equally thriving drug underworld.

He briefly worked at Newsday — “I was constantly doing delicatessen openings” — before quitting and moving to Paris in 1986.

In 2007, Mr. Greene, van Lohuizen and other photographers launched the Amsterdam-based Noor photo agency.

Mr. Greene’s photography appeared in many of the world’s best-known magazines, but he often had to finance his travels from his own shallow pocket.

“I live from hand to mouth,” he told the Times in 2010. “Let’s be real here. I don’t own an apartment. I don’t own a house. I don’t own a car. I don’t have any stocks and bonds. All I own are my cameras.”

Mr. Greene, who was married at least twice, had numerous girlfriends over the years but no children. Survivors include a brother.

Mr. Greene received five World Press Photo awards, among other honors, and in 2010 published a photographic memoir, “Black Passport.” He often spoke at international photography conferences.

In recent years, he had documented the environmental and human cost of the digital age, traveling to Nigeria, India, China and Pakistan, where people salvaged discarded electronic devices from waste dumps. He said he was not interested in quick-hit photography but preferred deep-immersion assignments in which he could explore complex visual tales.

“I think at the end of the day, we have to be storytellers,” Mr. Greene told Italian Vogue magazine in 2013. “Yeah, I think that you have to be obsessed.”