Last US Troops Leave Afghanistan Ending 20-Year War: Pentagon . The withdrawal of the US troops preceded the finish of August 31. The last flight left at 1929 GMT Monday - not long before the beginning of Tuesday in Kabul, he said. Departure cut off . How that interaction will unfurl is muddled. Everything considered, the US military spent more than $775 billion on tasks in Afghanistan since 2001, as indicated by the most recent accessible information from September 2019.