Name a common threat faced by expeditionary forces.

IEDs (Improvised Explosive Devices) are a common threat faced by expeditionary forces primarily because they are widely utilized by insurgents and enemy combatants in areas where conventional military tactics are employed. These devices can be placed in various locations and are often designed to detonate in response to the movement of troops or vehicles, leading to significant casualties and damage. Their prevalence in conflict zones makes them a constant concern for expeditionary forces who must remain vigilant and employ countermeasures while conducting operations.

The threat of IEDs is particularly relevant in asymmetrical warfare scenarios where traditional military advantages can be negated through the use of these low-cost, high-impact weapons. Successful expeditionary operations require thorough training and preparation to detect and neutralize IEDs, highlighting their critical standing as a common threat in this context.

While the other options present legitimate challenges, they do not encapsulate the unique and immediate threat posed by IEDs in the operational environment faced by expeditionary forces. For example, cyber attacks are significant but typically occur within the realm of information warfare, and while medical emergencies and supply chain disruptions can impact mission effectiveness, they do not threaten immediate physical safety in the same direct manner as IEDs.