In what context, if any, does the Quran address the topic of killing enemies?

The Quran contains verses mentioning killing in the context of warfare, primarily during the time of Prophet Muhammad, but these verses are usually understood within specific rules and conditions. These contexts generally relate to self-defense, fighting against oppression, and breaking treaties. It often emphasizes fair conduct during war and that the innocent should be spared. The Quran also stresses reconciliation and forgiveness, though it acknowledges the necessity of fighting in some instances.