The Inquiry

How did Trump’s personality and way of dealing with people lead to a trial in the Senate? The answer involves Trump’s long standing belief in conspiracy theories, his transactional way of doing business, the revolving door of staff turnover at the White House and his admiration for Russian president Vladimir Putin. With Tanya Beckett. ( President Trump departs the White House on the day of the House Impeachment Vote, Washington DC. Photo Credit: Mark Wilson/Getty Images)

On 25 July 2019, the President of the United States made a phone call to the recently-elected President of Ukraine - congratulating him on his party’s election victory. What Donald Trump said in that call to Volodymyr Zelensky has ended up threatening his own presidency, triggering the impeachment of the president. Donald Trump says his interest was in rooting out corruption. Meanwhile Joe Biden’s role in Ukraine was to do the same - root out corruption. The Inquiry asks why Ukraine has such a corruption problem. Presented by Ruth Alexander. (A Ukrainian flag flies in Independence Square in Kyiv, the capital of Ukraine. Photo credit: Pavlo Gonchar/Getty Images)

President Trump’s decision to assassinate Qasem Soleimani came as a shock to America’s foes and allies alike. He was Iran’s top general and has been described as one of the country’s most powerful figures, second only to the Supreme Leader Ayotollah Ali Khamenei. He was, effectively, head of Iran’s foreign policy. He’s been credited as being instrumental in the fight against ISIS but has also been accused of arming and supporting terror groups. But why did Donald Trump order his death? Presenter: Tanya Beckett Producer: John Murphy (Image: Lieutenant General Qasem Soleimani / Photo handout from the Iranian Supreme Leader's office)

What is the chance of the human race surviving the 21st century? There are many dangers – climate change for example, or nuclear war, or a pandemic, or planet Earth being hit by a giant asteroid. Around the world a number of research centres have sprung up to investigate and mitigate what’s called existential risk. How precarious is our civilisation and what can be done to stop a global catastrophe? David Edmonds talks to four expert witnesses to try and find the answer. (Apocalyptic landscape. Credit: Santoelia/ Getty images)

Despite heroic efforts to vaccinate against this crippling disease, why does it persist? The fight to eradicate polio is an amazing story: It began with a grassroots movement in the United States and led to a global campaign to wipe out a disease that can cause paralysis and even death. There is no cure, but countless cases have been prevented by an extraordinary campaign to vaccinate every child aged five and under. It’s an operation that requires access to some of the poorest and most remote regions of the world. But polio was supposed to have been eliminated by the year 2000. Nearly two decades later, new cases are still springing up. Why? Neal Razzell examines the challenges and the triumphs in the effort to rid the world of polio.