Rule 39

The obligation to take feasible precautions in attack applies equally to UAV/UCAV operations.

[Commentary]

  1. The law of international armed conflict has no provisions that are specific to UAV/UCAV. Therefore, the general requirements to take feasible precautions apply. The fact that a UAV/UCAV is unmanned does not relieve an attacker of taking such precautions. For the definition of UAV, see Rule 1 (dd). For the definition of UCAV, see Rule 1 (ee).

  2. UAVs can be a useful asset in complying with the obligation to take feasible precautions in attack. UAVs with on-board sensors will contribute to verification that an intended target is a lawful target (see Rule 32 (a) and Rule 35 (a)). Hence, if available and when their use is feasible, UAVs ought to be employed in order to enhance reliability of collateral damage estimates (especially when this can be done in real-time).

  3. With regard to remotely piloted UCAVs, UCAV operators must employ on-board and/or other reasonably available sensors and sources of intelligence, to the extent feasible, to verify the target and assess expected collateral damage (see Rule 32 (c) and Rule 35 (c)). The fact that the UCAV is unmanned does not necessarily detract from the reliability of information on which the decision to attack is based. Indeed, such assessments by remote operators may be more reliable than those of aircrews on the scene facing enemy defences and other distractions.

  4. In case of autonomous systems, the UCAV must only be programmed to engage potential targets based on reliable information that they are lawful targets. The performance of the sensors and the program identifying lawful targets must be comparable to that of manned aircraft or to that of remotely piloted (i.e. non-autonomous) UCAVs.

  5. The standards set forth in Rule 12 regarding doubt apply equally to UCAV attacks, whether autonomous or manned.

  6. When feasible, the options of using UCAVs in lieu of manned aircraft or other weapon systems, or vice versa, ought to be considered in determining how best to attack a target while avoiding — or, in any event, minimizing — collateral damage. For instance, use of a UCAV in circumstances in which visual identification of the target is necessary — either to reliably verify the target or to avoid excessive collateral damage — may be called for if defensive actions by the defending forces would likely impede visual identification by aircrews. Alternatively, a manned aircraft rather than a UCAV may be called for when its sensors are superior to those of a UCAV or where the visual identification by aircrews would be more reliable than images transmitted from the UCAV’s sensors to its operator.

Categories: G: Specifics of Air or Missile Operations