I've noticed a running theme in criticism of the status quo in both science and politics. Namely that matters are not perfect now, therefore the methods used now are insufficient. Iraq doesn't yet have a constitution and the opposition has not been silenced? Then it must be a complete quagmire and Bush should be impeached for getting us in there in the first place. Evolution can't explain all of the mechanisms of nature? Then evolution is completely useless and the guiding hand of Intelligence is necessary to explain the gaps. A very good post here on the Evolution/ID matter.
In science, the fact that there are questions is taken as evidence that science is insufficient for the task. I like to say that science is more about the questions it asks than the answers it finds. An old story goes that it is aerodynamically impossible for bublebees to fly. That such an obvious contradiction existed did not mean that the known laws of aerodynamics had to be discarded. Instead, further research was done and a deeper understanding of the mechanisms was realized.
In war, there are strategy and tactics. Strategy is the large, sweeping goals of a campaign. Strategy does not just leap from plan to reality with no intervening steps. Those steps happen where the plan meets reality, the realm of tactics, and tactics take time. Trying to predict how long that will take is like predicting the weather, we have some theories about general trends, but the particulars always throw in complications. Making a quantum analogy, predictions change the system. Name a deadline, and the circumstances under which the deadline was set has changed and the other side takes that into account and changes their plans.
In the end, my point is that plans and theories are not static, nor are they necessarily, if ever, perfect. Fundamental to methods of dealing with and explaining reality is that it must continue to conform to new information from reality. And it is not reasonable to claim that generals and scientists should have known from the beginning. If I had that type of knowledge I'd be the one doing the designing on my own.