The US is at the centre of an international row over claims to a slice of Syria's oil revenues.Read more
Reality Check team
The US president has again dismissed the impeachment inquiry as a "witch-hunt" and a "joke".
You might remember this name from the Obama years: Samantha Power. She started her career as a journalist covering the mass killing of Muslims by Serbs during the Bosnian war in the early 1990s. She wrote a Pulitzer Prize-winning book about her experience - arguing that American leaders repeatedly fail to halt genocides... Ms Power entered politics, eventually becoming the US ambassador to the UN. Now she's written a book about that experience. "The Education of an Idealist- a Memoir" charts her years in politics and how that changed her from an uncompromising idealist to a realist official. Power's time as a UN ambassador coincided with a crucial phase in the Syrian war. In 2012, Mr Obama had said that any use of chemical weapons by President Assad would cross a "red line", and she has been criticised for not standing firm to her earlier beliefs that military action by the US could have made a difference in the Syrian war as it did in the Bosnian war in the end. So when Samantha Power came into our studio to talk about her book, Dan Damon asked her why didn't the US take quick and decisive action in Syria?
President of the Executive Committee of the Syrian Democratic Council, Ilham Ahmed, on whether she feels the Syrian Kurds were betrayed by the United States, and are there links between themselves and the PKK? (Photo: The President of the Executive Committee of the Syrian Democratic Council, Ilham Ahmed. Credit: Reuters/Henry Nicholls)