US leak: Jack Teixeira arrested by FBI agents

Security services in the United States have arrested a 21-year-old Air Force guardsman suspected of leaking classified Pentagon documents; it's believed he posted the documents on a social media platform popular with video gamers.

We go to South Korea to find out more about the latest ballistic missile launched by the North and what it tells us about that country's nuclear capability.

And Mariko Oi joins us to tell us about a row between Twitter and Substack - the latter has just launched something called "Notes" and it's been accused of cloning Twitter.