The deadly port explosion was one of the largest non-nuclear blasts in history, sparked by dangerous chemicals sitting neglected for years. More than 200 people were killed, thousands were injured, and countless others bear the invisible wounds inflamed by unanswered questions and the lack of accountability. Georges Kettaneh joins Christiane from Beirut.

The state of Louisiana is experiencing its worst COVID-19 surge yet, with an all-time high in hospitalizations. Democratic Governor John Bel Edwards has reinstated mask mandates in an effort to combat infections. And here he is talking to our Walter Isaacson about wrestling with the COVID-19 crisis and what good government can do.

California Governor Gavin Newsom faces a rare recall election this September and is trying to rally . In addition to COVID spiking in the state again, he's dealing with contentious debates over mask mandates, raging wildfires, and drought plaguing nearly half the state. A lot to talk about with the Chief Executive of America's most populous state. He joins Christiane from Sacramento.

Robin D'Angelo is famed for her bestselling book "White Fragility." D'Angelo's work aims to educate white progressives on the part they play within a racist culture. It's a theme she continues in her new book "Nice Racism." Here she is explaining her work and the criticism that has been leveled against her to Michel Martin.

President-Elect Ebrahim Raisi was officially accepted by Iran's Supreme leader Ayatollah Ali Khamenei ahead of Thursday's inauguration. Raisi is a much more hardline and anti-western politician than the outgoing president Hassan Rouhani. Correspondent Fred Pleitgen takes a look at what's top of Raisi's to-do list and gives an update on the nuclear deal.

This summer, we've seen extreme weather spread everywhere. Turkey is one of the latest countries to be hit where at least 8 people have died in more than 100 wildfires in the last week. We are witnessing the slow destruction of the natural world -- an issue highlighted by the award-winning Turkish-British novelist Elif Shafak in her latest book, "The Island of Missing Trees."

Only half the U.S. population is fully vaccinated. The Federal government is trying to raise vaccine enthusiasm with treats and perks. "What if the unvaccinated can’t be persuaded?" is the title of Ezra Klein's latest column for the New York Times. He joins Christiane from California.

A recent internal document from the CDC reveals that it's as contagious as chickenpox and it carries an increased risk of severe illness and hospitalization. Michael Osterholm is the Director for Infectious Disease, Research and Policy at the University of Minnesota. He speaks with our Walter Isaacson about how the U.S. should respond and what can be learned from other countries.

There have been dramatic developments at the Olympics. Belarusian sprinter Krystina Tsimanouskaya was at the Polish Embassy today, speaking about political asylum. Another big story is Simone Biles, who is returning to compete. Correspondent Selina Wang is on the ground in Tokyo and speaks to Christiane.

In France, President Macron is putting pressure on the holdouts with a tough 'no dose, no fun' approach -- banning the unvaccinated from theatres, restaurants and cinemas. The tough-love approach seems to be working. Nathalie Loiseau, French member of European Parliament, joins the program to discuss her country's policies.

Saad Mohseni heads the biggest media organization in Afghanistan, the Moby Media Group, which includes Tolo TV. His latest article for the digital newsletter Air Mail, "The View from Here," gives a stark warning of what Afghans stand to lose if the Taliban seize power. He joins Bianna from Greece.

Imagine writing a memoir detailing the last days of your parents' lives. Now imagine that one of your parents is the late literary giant and Nobel laureate Gabriel García Márquez. Rodrigo García joins Bianna to discuss his creative process and his new book, "A Farewell to Gabo and Mercedes."

The Delta variant is surging in the U.S. and around the world, and it's even more troubling than was first thought. That's according to an internal document from the CDC. The public health agency now believes the strain is as contagious as the chickenpox. Dr. Reed Tuckson joins the program to unpack this news.

Over 100 CEOs have come together to form the organization CEO Action for Racial Equity. Its goal: addressing systemic racism and creating lasting change through public policy. The CEO of this initiative, Roy Weathers, and Denny's CEO John Miller are determined not to let politics stand in their way. They speak with Hari Sreenivasan about their plan.

After days of uncertainty, an important act of diplomacy has finally taken place, as announced to the world on President Biden’s Twitter feed. Biden posted a photograph of his meeting with Belarus’s opposition leader, Svetlana Tikhanovskaya, saying he was honored to meet with her at the White House. Tikhanovskaya has been touring the U.S. to raise awareness of her people’s struggle for democracy.

In Russia, President Putin’s efforts to suppress journalism show no sign of abating. Just yesterday, Russian security officers raided the home of Roman Dobrohotov, editor of the independent news site The Insider. Alexey Kovalev knows what it’s like to report from under the heavy hand of the Russian state and joins the show to discuss.

American gymnast Suni Lee celebrated her gold medal in women’s gymnastics in Tokyo today. Lee’s teammate Simone Biles cheered her on from the sidelines after withdrawing from competition earlier this week to protect her mental health. Dr. Colleen Hacker is a mental skills coach for Olympic athletes and an authority on the psychology of peak performance.

Today President Biden announced a vaccination requirement for federal workers, as vaccine hesitancy persists despite the rapid spread of the Delta variant. In Tennessee, only 39% are inoculated and even Republican senators are urging people to get protected. Two Tennessean doctors join the show to discuss.

Chesa Boudin was elected in 2019 on a progressive platform aimed at ending mass incarceration and addressing the root causes of crime. Now, just two years into his tenure, Boudin faces a recall effort to remove him from office. Michel Martin speaks with Boudin about a rise in violent crime and how the jailing of his parents informed his views on criminal justice.

Action on climate must come not just from individuals, but also from companies and governments. Lawyers and the courts are also playing their part, something James Thornton is particularly aware of. He's the CEO of ClientEarth, a team of environmental lawyers dedicated to representing and defending the oceans, forests, air, and the very survival of our natural world. The team has 166 active cases.