The Johnson administration became obsessed with Vietnam, the Kremlin became obsessed with Afghanistan and the Reagan administration became obsessed with Nicaragua. That led to bad troubles for the Reagan administration. Big countries have to pick their fights very carefully.
Victory has to be certain in a fight with a small enemy.
If not, things can get out of hand. After all, Sheriff Reagan mostly fired in the air, harmlessly busting up the bullies on a weekend drunk. And besides, in the heat of a national pep rally, any downbeat voice was easily scored as whiny and defeatist. We'll talk of just how much that figures to cost him. Energy analysts call the lack of action irresponsible.