johnlambert - You are taking the original question out of context now (use of armed force during conflict), but I will try and respond to your point.
Democratic nations should have a moral difficulty in using armed force. They must follow the widest and most positive moral intention underlying the rule of law. International law, expressed in the UN Charter, governs what constitutes a just war; and properly interpreted they allow the right of self defence (which may be collective), and intervention under very strict conditions (articles 42 and 51). Briefly the legal and ethical factors codified in the international law documents are determined by criteria namely:
- Just cause (consequences of illegal acts).
- Competent authority initiates and guides the use of force (normally a government or alliance).
- Right intention (not revenge or punishment).
- Last resort (all other means having been tried).
- Proportionality of the force used to limit destruction of life and property.
- Reasonable hope for success (peace)
When force is sanctioned and then used, armed forces are legally bound to take actions likely to lead to death, drowning, breaking of lives and limbs, causing destruction that under peacetime conditions would be described as hideous crimes and brutal cruelties (mass murder, wanton destruction, etc.).
The duty of British Servicemen also falls within the British Defence Doctrine & British Maritime Doctrine.
Decisions on the use of armed force are normally left to politicians, but service officers and civil servants are duty bound to advise and judge when force is appropriate, and how far its use will achieve a constructive purpose. The only legitimate object of war is a more perfect peace.