The Civil War is a better example than Vietnam -- not only because public support died in the US with Nixon's "Guam doctrine", but because it wasn't a particularly existential struggle for the US -- that is, my point was that there is a "natural selection" of social institutions based on military defeats. (Also, South Vietnam was an interesting question in its own right: to what extent is a strong-man or dictator a "bureaucrat"? Chinese civilizations are a grand example of a clear bureaucracy with a central dictator, so the answer isn't trivially either "not at all" or "absolutely.")

Just to be clear: I am not arguing against agility and I think that the central agile ability -- the ability to fail cheaply -- is probably the most important feature in many areas, including some military conquests. (One of the most interesting applications of cheap failure is interface design. If you can test a new idea cheaply it allows feedback loops which make you feel like you're really "interacting with something.")

In any case, you've given me some food for thought, and thanks for that.