Afghan problems started with the invasion of the Soviets, who were anything but “tribal.”
It was an attempt by the then Afghan govt to impose a system of communism, which was alien to the society they wished to govern.
Prior to the Soviet Invasion, the Afghans were relatively prosperous. Infact, with the women in skirts and the general beauty of cities like Kabul as your backdrop, you would never have guessed it was a country run by a tribal system of governance.