Don't count Yevgeny Prigozhin out

In late June, the oligarch, longtime Putin ally, and Wagner mercenary group chief Yevgeny Prigozhin shocked the world (and Vladimir Putin) when he marched his troops through Russia in what appeared to be a coup against Moscow. Although he backed down, Marie Yovanovitch, former US Ambassador to Ukraine, thinks the story is far from over.

"There are probably a number of different phases of the Prigozhin rebellion," Yovanovitch tells Ian Bremmer in the latest episode of GZERO World, "and we're not at the end of it yet."

So why hasn't Putin more brutally punished Prigozhin and his followers for insubordination? And how should the West take advantage of this internal strife within Russia?

Watch this episode: Ukraine's counteroffensive on the brink

And watch GZERO World with Ian Bremmer every week on gzeromedia.com/gzeroworld and on US public television. Check local listings.