The main issue discussed in this article is that not only were the predictions made by the U.S. analysts and General Milley wrong (they expected Ukraine to fall in 72 hrs), because of their over-reliance on them they were not prepared to think about what would happen if their prediction was wrong. A large point made is that the U.S. analysts did not perform enough assessment on Russia's shortcomings, and opted to assume the most expected outcome would take place, rather than contingencies. It highlights the complexity of prediction when dealing with human behavior as opposed to other organisms.
A slightly related article from 2009 on the perils of making predictions for defense spending