When the Soviets left, Najibullah's army lasted 2 years against the Taliban (he lost all his support and funding from the collapsing USSR. The Talibs were funded and armed by the US of A). The US '20 years of training' Afghan army lasted less than a week.

The US army never held any meaningful territory in Afghanistan...no one ever does ask the British we learned the hard way...twice. You just occupied strongholds in forts like in Helmand. And highly fortified air bases like Bagram. Patrolling outside these bases was extremely hazardous.

The Soviets went into Afghanistan in 1979 and withdrew 10 years later. They did not invade they were invited in to help fight the US/UK backed terrorists by the progressive legitimate government under Najibullah (Women rights guaranteed by law including free education up to University level) The US sought to destroy these women's rights and replace it with a toxic oppressive religious fundamentalism..and succeeded. So win there... I suppose. But the US would return ten years later..spend 2.1 trillion dollars of US tax payers money...over 22,000 casualties and leave the country to the Taliban they had been fighting for twenty years. It was a win for the arms dealers and heroin traders (the US has a lot of opioid addicts, developing this lucrative market over the same twenty years..hey, all that heroin needs to go somewhere!) But that is how America wins...they don't fight to win...win what? Win contracts that's what. So yeah, the never winning army lost but the arms suppliers know they won....all the way to the bank.