Will Putin invade Ukraine? That's the million-dollar question. Joe Biden certainly seems to think so. But whether Vladimir Putin will actually do it, or is just playing political chess, is anyone's guess.

Putin has long griped about the collapse of the Soviet Union, which explains how he feels about Ukraine. The US and NATO accuse him of posturing, but he thinks NATO is doing the same.

In a new episode of GZERO World with Ian Bremmer, Ukraine expert Alina Polyakova says the Russian leader has put a “noose” around Ukraine with his troop build-up along the border and cyberattacks. Putin has responded to Western diplomacy with demands that are impossible to meet.