No, we have not learned anything from or since 9/11. All we did was follow Russia’s footsteps and experience in Afghanistan. Result, thousand of dead in misguided Bush war in Iraq, Pakistan and India are now nuclear powers, and the middle east is unsafer now than ever before. Worse, we ignored and cozied up to Saudi Arabia, whose government and citizens financed and conducted the attack on 9/11.
At least the Soviets understood that EVERYBODY in Afghanistan (even if they’re temporarily fighting on your side) are enemies.