They call each other Emmanuel and Vladimir - but despite the informal tone, a fateful negotiation is taking place. During France's presidency of the EU, President Macron takes on the task of negotiating with President Putin in an attempt to prevent an invasion of Ukraine. For the first time, we get to follow the diplomatic game behind the scenes and hear parts of their phone conversations.

David Letterman journeys to Kyiv, Ukraine for a stirring, personal and in-depth conversation with President Volodymyr Zelenskyy.