OK, reading ONLY the story: "Reports indicate that more than 250 full time fighters reside in the city and in the surrounding villages."
It seems to me that the Marine commanders knew the potential for large-scale hostile activity.
Even if there had been only low-level activity in the past, basing current actions on past results, given the estimates of opposing forces in the area, still doesn't seem to be a very good idea. It just seems to be a potential recipe for disaster if the enemy does sortie in force.
If the area commanders have access to unlimited forces, then you can deal with theoretical problems. If you have limited forces, you apply them proportionally to the threat. It's not simply an issue of there being 250+ fighters in an area; it's a question of whether all 250+ have ever banded together at one time to achieve one objective. This village was described as a source of issues for the entire region, not just the village itself.
As for fighting the last war, that comes about as a result of the post-conflict analysis that goes on. They see what went wrong or what is the immediately/largest threat, and they work to fix that. All too often, they do so at the expense of anticipating where the next conflict might be. However, that's not necessarily what is at work here. This is about allocation of resources due to scarcity, not a failure to grasp what is needed.
