• Beating a prisoner is clearly in breach of the Laws of Armed Conflict and is therefore forbidden.

• It is very likely to be illegal according to the law of the land you are in as well.

• One can accept that there might be cultural differences between forces in a coalition, but there are still certain types of action that are completely unjustifiable.

• Knowing what to do about it is harder though. Do you have sufficient authority to act, or do you need to find someone who does?

‘Military operations do not take place in a vacuum. In the messy moral reality of coalition military operations, careful consideration also needs to be made of the likely impact of one’s actions beyond the immediate situation. After the first part of the question has been answered - ‘am I justified in intervening to prevent an action I disagree with?’ - a military officer in a coalition environment must also make a prudential calculation to answer the second question - ‘should I act?’ The likely costs and benefits of action must be carefully weighed to determine if the ‘right’ course of action really is also the ‘best’ one once the broader context has been taken into account.’

See 8 of Spades

David Whetham, ‘The Challenges of Ethical Relativism in a Coalition Environment’, Journal of Military Ethics, 7 (2008), p313.