Two things that have emerged from the ashes of the World Trade Center are the urgent case of Afghanistan, the previously little-known country in which the Al Qaeda hijackers trained, and the Tribeca Film Festival. According to the festival’s executive director, Peter Scarlet, the two have been linked since September 11, 2001.

“I’ve felt ever since arriving at TFF in 2002 that the fest’s original mission — putting Lower Manhattan back on its feet economically and spiritually — encompassed the need to open our windows and our eyes to what’s happening in the rest of the world,” Mr. Scarlet said. “Especially to a place like Afghanistan, to which we’re forever tied by 9/11.”

This year’s lineup reflects that bond — which is surely part bondage — more than ever. The recent glut of Iraq documentaries shows (once again) that compelling stories spill out of war, but the Tribeca program suggests something more surprising: that Afghanistan, for filmmakers at least, has become the primary front. Security concerns have something to do with it — Mr. Scarlet noted that it has become more difficult to capture Iraq on camera “without risking the loss of several major body parts” — but so does an increasing sense that Afghanistan matters, which has become something of a party line among Tribeca officials.

“Afghanistan is in trouble,” festival programmer Nancy Schafer announced at a press conference last week. “We need to bring the spotlight back.”

“Taxi to the Dark Side” brings an interrogation lamp. Directed by Alex Gibney, who earned an Oscar nomination for his previous film, “Enron: The Smartest Guys in the Room,” this engrossing examination of American treatment of suspected terrorists is one of the most talked about films at the festival. Mr. Gibney’s investigation of prisoner abuse begins at Bagram air base in Afghanistan, the military detention center where a young Afghan taxi driver was found dead in his cell in December 2002. Evidence later showed he was killed by his American captors.

The film’s inquest extends to Guantanamo Bay and to the infamous corridors of Abu Ghraib, but Afghanistan, the original testing ground for America’s war on terror, is its real starting point. “Taxi” argues that when the U.S. military entered the country to put down the Taliban, American values didn’t make it over intact. The young, poorly trained soldiers charged with extracting information from prisoners — a handful of whom are interviewed here, in dramatic chiaroscuro lighting — were thrown into not only an alien land but treacherous moral territory, with superiors seemingly unwilling to guide them through it. The old rules didn’t apply; the gloves, as Vice President Cheney memorably said, came off. But then what? According to the film’s many interviewees, including those who served at Bagram, the Pentagon had no clear policy for detainee treatment — only, in the words of one legal expert, a “fog of ambiguity coupled with great pressure to bring results.” When that combustible mix exploded at Abu Ghraib, the collateral damage, both in terms of human rights and public relations, was shocking — and Mr. Gibney has the footage to prove it.

Beth Murphy’s “Beyond Belief” couldn’t be more different from Mr. Gibney’s dry-eyed exposé, but it is no less dramatic, and a good deal less self-important. There’s something decidedly feminine about this emotional tale of two September 11 widows and their counterparts in Afghanistan, but it is much more than a woman’s film. (That is to say, men should bring hankies, too.) It’s impossible not to be stirred by the “post-traumatic growth” of Massachusetts residents Susan Retik and Patti Quigley, both of whom were pregnant when their husbands boarded planes that crashed into the World Trade Center. Somewhat reluctantly, the two women agreed to meet; they bonded instantly, and organized a fund-raising bike ride from Ground Zero to Boston. The proceeds supplied chickens — and a way of earning a modest income — to about 500 destitute Afghan widows.

These two remarkable women did not, as Ms. Murphy’s wonderfully touching film illustrates, embark on this mission to escape their grief; their grief is wrapped up in it. “I have tried to turn this into something other than hatred,” Ms. Quigley says of her loss. Visiting war-torn Afghanistan requires both mothers to leave their children behind, and the kidnapping of their liaison in Kabul gives them pause, but ultimately they meet their long-suffering beneficiaries. When they do, the yawning gulf between two very different ways of life emerges with shattering clarity; but so does Ms. Retik’s observation that “a mother is a mother is a mother.”

The homegrown documentary “Postcards From Tora Bora” also explores Afghanistan through contrasts. After 20 years in North America, narrator and co-director Wazhmah Osman filmed her return to the country of her childhood, which her family fled following the 1979 Soviet invasion. Ms. Osman’s home movies from Afghanistan, “the only tangible things left of my past,” depict women in skirts and dapper young men playing volleyball. It’s a far cry from the ruin she revisits as an adult. In Kabul, Ms. Osman carries around a photo of the capital from the 1970’s that stumps local cab drivers: The river it shows is now dry, the tall buildings carcasses.

“Zolykha’s Secret,” the only Afghan-produced work in this year’s festival, is a fantasy-tinged drama set in a remote village. Written and directed by Horace Ahmad Shansab, this primitive film is poignant, if only because it makes the growing pains of the country’s national cinema painfully obvious. (“Osama,” the elegant Afghan film that won the 2004 Golden Globe for Best Foreign Film, was without a doubt a small miracle.) Mr. Shansab, an American-trained filmmaker, financed the production himself and also tutored most of the crew. His film’s main virtue is its focus on life under the Taliban, a starkly austere portrait of which begins to emerge through the melodrama.

The battleground of Afghanistan also haunts the experimental Dutch film “Why Didn’t Anybody Tell Me It Would Become This Bad in Afghanistan.” Director Cyrus Frisch’s first-person narrative — if it can be called that — was shot almost entirely on a cell phone, and the result is something between an impressionist rendering of Amsterdam and a Hans Hoffmann canvas in motion. More than anything else, this 70-minute document of a day in the life of a Dutch veteran of the Afghanistan war reveals a state of mind terrorism has introduced to the West: the fragmented image, the trembling camera-phone, the vague sense of menace are all part of it. Mr. Frisch’s unconventional cinema may not be for everyone, but this is that rare film in which Afghanistan really gets under your skin.