They say you learn from history, but that is not often the truth. We went into Viet Nam after refusing to assist the French (so they finally left). Then we left and nothing was settled except the country was united under a single flag, and not the one we were fighting for. Seems like Afghanistan was different to start with since we went in to find bin Laden. After upsetting their government, now we find, 15 years later, we are still there, at war. Lesson learned: NONE.