Trump surrendered to the Taliban before he left office
The US military had already been losing ground in Afghanistan for years. There was no “winning” in Afghanistan for the US any more than there had been for Russia 30 years prior. Trump oversaw a negotiated peace (which he renegged on before he’d even left office and then Biden rennegged on as soon as he was in office) and began officially recalling units from the front lines. Biden choose to continue withdrawing troops because it was exhausting US military resources far in excess of any perceived value.
The US military had already been losing ground in Afghanistan for years. There was no “winning” in Afghanistan for the US any more than there had been for Russia 30 years prior. Trump oversaw a negotiated peace (which he renegged on before he’d even left office and then Biden rennegged on as soon as he was in office) and began officially recalling units from the front lines. Biden choose to continue withdrawing troops because it was exhausting US military resources far in excess of any perceived value.