As US-led troops withdraw after 20 years, the Taliban have made a swift return to power.
Four presidents have overseen the war in Afghanistan - with four different approaches.
Charmaine Cozier asks which of them is most responsible for how events have unfolded and ultimately setting the path to failure.
Produced by Ben Cooper
Researched by Sally Abrahams
(Image: A US marine walks past an American flag attached to concertina wire at Camp Rhino in Southern Afghanistan. Credit: Rick Loomis/Los Angeles Times/AFP via Getty Images)
