Nord Stream explosion mystery: We need proof, says Estonia's PM Kaja Kallas

Who blew up the Nord Stream pipelines? We still don't know, and that's a pretty troubling thought given it's the single biggest attack outside of Ukraine during the war. Multiple investigations determined the September 2022 explosions of Nord Stream 1 and 2 were sabotaged, and the west immediately blamed the Russians. But months after the attack, there's still no evidence of Russian involvement and the explosions are still an international unsolved mystery.

At the Munich Security Conference, Estonian Prime Minister Kaja Kallas sat down with GZERO World and Ian Bremmer, where he asked her directly if she buys the story of Russian involvement. Kallas has an interesting theory about a possible pipeline mix-up, and says that the question of who is responsible is still an open one. Ultimately, Kallas says there must be proof if there is going to be accountability, and achieving that accountability might mean rethinking international law.

Catch Ian Bremmer's full interview with Kallas in this week's episode of "GZERO World with Ian Bremmer," airing on US public television stations nationwide. Check local listings.