Describe the principle of proportionality in naval ROE and provide a brief example scenario.

• A. Force used must always be maximal at first sign of threat.
• B. Proportionality means only non-lethal measures are allowed.
• C. Force used must be proportional to the objective and the threat; example escalating from presence to limited force if needed.
• D. Proportionality is only applicable during peacetime.

Answer: (C)

The principle of proportionality in naval ROE means the force used must match the objective and the threat, and be limited to what is necessary to achieve that objective while minimizing unnecessary harm. In practice you start with presence and warning, then apply non-lethal measures if needed, and only escalate to greater force if the threat remains or escalates. The idea is to use exactly what is required to deter or defeat the threat, not more.

Example: a warship enforcing a blockade observes a small boat approaching the exclusion zone. The crew first makes their presence known and issues clear warnings for the boat to halt. If it complies, no further action is taken. If it disregards the warnings and threatens the ship, they might employ non-lethal measures such as signaling and, if appropriate, a non-lethal device to deter. If the threat continues or increases—such as attempting to ram the ship or launch a weapon—they escalate to limited force designed to stop the vessel and prevent breach of the blockade. Only if the situation remains dangerous would force beyond the limited level be used, and always aiming to stop the threat with the least amount of force necessary.

The other options don’t fit because maximal force at the first sign of threat is not proportional, only non-lethal measures do not always suffice, and proportionality applies in both combat and non-peaceful operations, not just peacetime.