World leaders gathered in Germany on Friday for the start of the annual Munich Security Conference. Nick Schifrin reports from the conference and sits down with one of the attendees, Estonian Prime Minister Kaja Kallas, for an interview. Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG Find more from PBS NewsHour at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6 Follow us: TikTok: https://www.tiktok.com/@pbsnews Twitter: http://www.twitter.com/newshour Instagram: http://www.instagram.com/newshour Facebook: http://www.pbs.org/newshour Subscribe: PBS NewsHour podcasts: https://www.pbs.org/newshour/podcasts Newsletters: https://www.pbs.org/newshour/subscribe