The final reason for recurring failure is the tendency to rely on the same people, no matter what their past track records have been. We’ve seen a revolving door of (unsuccessful) Middle East peace negotiators who then spend their retirements giving advice on how future peace negotiations should be conducted. We’ve got a CIA director who’s been centrally involved in U.S. counterterrorism policy since the early 1990s, and who continues to enjoy the president’s confidence despite a dodgy relationship with the truth and a conspicuous lack of policy success. We’ve got famous generals who were better at self-promotion than at winning wars, yet whose advice on what to do today is still eagerly sought. And of course we’ve got a large community of hawkish pundits offering up the same bellicose advice, with no acknowledgement of how disastrously their past recommendations have fared. The result is that U.S. policy continues to run on the same familiar tracks, and with more or less the same unhappy results.
Just like the war on drugs.
I can't speak for the personnel of the war on drugs, but I know that some of the biggest cheerleaders for war with Iran (think Dick Cheney)--instead of being disgraced as war criminals and emptying bedpans in VA hospitals for the rest of their miserable lives--are somehow considered elder statesmen whose opinions on the matter, matter.