What is a significant drawback of using berms and ditches for passive defense?

The significant drawback of using berms and ditches for passive defense lies in the requirement for heavy equipment. Constructing berms and ditches typically involves moving substantial amounts of earth, which necessitates machinery like bulldozers or excavators. These resources can be costly and may not always be readily available, especially in remote locations or situations where rapid deployment of defenses is critical. Consequently, without access to the appropriate heavy equipment, the effectiveness and timeliness of implementing these defensive structures can be severely compromised.

While other factors such as cost, breach vulnerability, and construction time might influence the overall strategy for passive defense, the dependence on heavy equipment fundamentally impacts the feasibility and speed of establishing effective protective measures. In scenarios where quick fortification is essential, waiting for equipment or dealing with logistical challenges can hinder overall defense preparedness.