Julian Fellowes is writer-producer of feel-good mega-hit “Downton Abbey,” the upstairs-downstairs drama that’s full of nostalgia for old-fashioned British grandeur. The award-winning TV series is now a film, with all the familiar characters returning to the big screen. Fellowes joins the program from New York to talk about what keeps pulling him – and us – back to this bygone era.

Today, young people all over the world participate in the global climate strike. Fighting the climate crisis is a personal and moral decision for author Jonathan Safran Foer, who has gone from writing acclaimed novels to penning impassioned non-fiction decrying climate inaction. His latest book “We Are the Weather” explains how “saving the planet begins at breakfast.”

Inspired by Swedish schoolgirl Greta Thunberg, millions of young people across the world plan to come out on strike from school to demand climate action tomorrow. Xiuhtezcatl Martinez, one of the young organizers of the strike, has been protesting since he was six years old, and coming from indigenous Mexican descent, believes protecting the Earth is his spiritual duty.

Benjamin Netanyahu, the longest-serving leader in Israel’s history, is staring into the abyss. This week voters went to the polls for the second time in five months, and again neither Netanyahu nor his main rival Benny Gantz gained an outright majority. Dan Meridor and Ronen Bergman discuss what this means for Israel's future.

This year marks 400 years since the first African slaves arrived on American shores, and despite a civil war, this country has never had a serious truth and reconciliation effort. Moral philosopher Susan Neiman joins Christiane Amanpour to discuss her new book "Learning from the Germans," which reflects on how the U.S. can atone for its sins.

As president of Microsoft, Brad Smith leads one of the world’s most valuable companies. His new book “Tools and Weapons” – co-authored with Carol Ann Browne – pulls back the curtain on Microsoft, as the company grapples with the ethical questions that come with technology like AI. Smith sits down with Hari to explain why he’s one of the few tech leaders today calling for more privacy regulation.

The climate crisis is having a devastating effect not just on the places we live, but also on our human rights. As the existential issue of our time, it will take center stage at this year’s UN General Assembly next week. Michelle Bachelet joins the program from Geneva to discuss what concrete action world leaders can take when they convene.

Sci-fi epic “Ad Astra” sees Brad Pitt tackle a space odyssey for the first time, as he plays an astronaut sent to the outer edges of the solar system to find his long last father. But, as well as a space adventure, it’s also a profound meditation on masculinity and vulnerability, subjects that he tells Christiane are close to his heart.

Former U.S. Ambassador Samantha Power's first book on genocide, “A Problem from Hell,” won her a Pulitzer Prize. But when she served on President Obama’s National Security Council and later as Ambassador to the United Nations, Power found that the road to hell is often paved with good intentions. She sits down with Walter Isaacson to discuss her new memoir “The Education of an Idealist.”

In the U.K., the Supreme Court is hearing arguments in what will surely be one of its most momentous decisions in years: whether Prime Minister Boris Johnson broke the law by asking the Queen to suspend parliament ahead of the Brexit deadline next month. Former U.K. Foreign Secretary David Miliband weighs in on this and another ongoing international crisis: the attack on Saudi oil installations.

Christy Turlington Burns was one of the original supermodels. She has walked thousands of runways and appeared on countless magazine covers, including most recently British Vogue’s September issue. But her focus for nearly a decade has been the issue of maternal mortality. She joins Christiane in New York to explain why this cause hits home for her.

In modern music, perhaps no other style is more quintessentially American than country music. Legendary documentary filmmaker Ken Burns has turned his attention to this art form in his new series, “Country Music,” in which he explores the remarkable stories of the people and places behind the genre. He joins Walter Isaacson to discuss what surprised him most about the journey.

Levels of anxiety and depression are skyrocketing in what professionals are calling a mental health crisis. Psychologist Laurie Santos is working hard to reverse these trends. Her class on happiness was the most popular course in Yale University’s history, and it has now been adapted into podcast form. She joins the program to explain how she helps her students combat daily stress.

World oil prices are soaring after an audacious attack on two critical Saudi oil fields. Yemen’s Iran-backed Houthi rebels claim they’re behind the strikes, but the U.S. asserts Iran is solely responsible, while Saudi Arabia itself says “all practical evidence” shows Iranian weapons were used. Vali Nasr and John Kirby join the program to break down what all this means for U.S.-Iran relations.

How do you get beyond fiery debates and foster dialogue? Reverend Irene Monroe describes herself as a black, lesbian, radical feminist who co-hosts the new podcast “All Rev’d Up," where she discusses current issues with an evangelical colleague. She sits down with Michel to talk about the need for dialogue between people of different views. Listen to “All Rev’d Up" at https://allrevdup.org/.

In her new book, journalist Azadeh Moaveni follows 13 women who were just girls when they left their home countries to marry militants. She joins the program in London to discuss the lives of the wives, widows and children of ISIS militants who are now languishing in refugee camps across war-torn Syria.

Another week, another Democratic presidential debate. The focus remains firmly on the contrast between frontrunner Joe Biden and his nearest challengers: Bernie Sanders and Elizabeth Warren. Those differences highlight the struggle not just for the nomination, but for the Democratic Party's future. Former strategists from both parties—Mark McKinnon and David Axelrod—join the program to discuss.

American students today owe a staggering $1.5 trillion in loans – that’s $28,000 in debt for the average graduate. But is it worth it? In his new book, “The Years That Matter Most,” author Paul Tough reminds us that the university system is already tilted towards the wealthy. He sits down with Michel Martin to discuss how inequality has come to define higher education.

Mark Sanford has become the third Republican to challenge President Trump in his own back yard, as the former Governor of South Carolina announced his bid for president this week. He joins the program from his home state to discuss his longshot bid for the White House.

Lily Tomlin and Jane Wagner's decades-long relationship has navigated extraordinary changing times, and now a major retrospective at Lincoln Center, “Two Free Women,” is celebrating their work. They speak with Christiane from L.A. to talk about their careers, partnership and this well-deserved honor.