How do we avert nuclear disaster in 2023?

Rafael Grossi has a very tough job as head of the UN's nuclear watchdog. But he's an optimist.

Still, the stakes are very high.

We've got North Korea building even more nukes. Russia turned into a rogue state that controls Europe's largest power plant in Ukraine, which is still at risk of an accident. And Iran getting closer to getting the bomb.

Last but not last, there's the global race to build smaller, faster tactical nukes.

Watch the GZERO World episode: Rogue states gone nuclear and the watchdog working to avert disaster