On Aug. 15, 2021, the Taliban swept back to power in Afghanistan. By the end of the month, US forces had departed after two decades of war.

President Joe Biden made good on his promise to bring the troops home before the 20th anniversary of 9/11. But the withdrawal was very messy, and Afghan institutions and army were not ready to resist the Taliban.

A year on, the country remains in shambles, Ian Bremmer explains on GZERO World.