There is a specific kind of operational vulnerability that intelligence organizations rarely discuss openly, not because it is classified, but because acknowledging it feels uncomfortable. It goes like this:
An officer spends four years in a posting. In that time, they build a complete mental map of the threat environment in their jurisdiction, source networks cultivated over years, the behavioural patterns of persons of interest, the significance of events that appear unrelated to anyone who was not there, the historical context that makes current intelligence readable. They know which informant to trust, which report to discount, and where the gaps in the official record are.