The intelligence may have been there - but the ability to draw conclusions unbiased by what Americans needed to believe was not, says Elliot Ackerman, a former US marine who served four tours in Afghanistan and has just come out with a book on the American pullout from Afghanistan called "The Fifth Act."

America's chaotic withdrawal a year ago stands in stark contrast to the highly coordinated US and NATO response to Russia's war. On GZERO World, Ackerman tells Ian Bremmer that when it comes to the Russian invasion of Ukraine, the US had a degree of objectivity it had lost after 20 years in Afghanistan. The war, he explained, had come to define our military thinking and intelligence capability because the US was involved there for such a long time.