NATO’s power and function is not quite as Trump describes it

Over the weekend, former President Donald Trump said that members of NATO had to pay their “bills” and that if they didn’t, Russia could do as it pleases to them. His statements and skepticism of NATO in the past have prompted members to invest more in their defense, but what exactly does his attitude towards NATO say about the idea of collective security and how it actually works? Host Marco Werman talks with Marion Messmer, a senior research fellow for the International Security Programme at Chatham House.