When the Marines did leave the Caribbean, the result they witnessed in each occupation was the worst of all worlds: dictators used the coercive power of national constabularies to destroy, rather than build up, what incipient democracy there was. Anastazio Somoza in Nicaragua, Rafael Trujillo in the Dominican Republic, and eventually François Duvalier in Haiti crushed caudillos and “nationalized” power without the required nationalism.
The lessons for Afghanistan today are dispiriting and opaque. There will be no happy ending, no riding into the sunset. Leaving earlier rather than later, as most Americans seem to want, makes sense, but isn’t a panacea. Afghans will sooner or later have to face their own demons and progress at their own pace. Peoples cannot be forced into nationalism; they must build it through their own initiative, trauma, and tears.
Colonialism has consequences. The longer you go, the more you get pro-U.S. elites entrenched in power that subsequently generate animosity and resentment, thus giving birth to rebellions that in the long-term make the situation even worse.