Consequently, jus ad bellum comprises several conditions but most importantly: just cause and proportionality. This gives people a guide whether it’s lawful to enter a war or not. However, this is only one part of the theory of the just war. Nevertheless, it can be seen above that jus ad bellum can be debated throughout, showing that there is no definitive theory of a just war, as it is normatively theorised.

The second section begins deciphering jus in bello or what actions can we classify as permissible in just wars (Begby et al (2006b), Page 323).

First, it is never just to intentionally kill innocent people in wars, supported by Vittola’s first proposition. This is widely accepted as ‘all people have a right not to be killed’ and if a soldier does, they have violated that right and lost their right. This is further supported by “non-combatant immunity” (Frowe (2011), Page 151), which leads to the question of combatant qualification mentioned later in the essay. This is corroborated by the bombing of Nagasaki and Hiroshima, ending the Second World War, where millions were intently killed, just to secure the aim of war. However, sometimes civilians are accidentally killed through wars to achieve their goal of peace and security. This is supported by Vittola, who implies proportionality again to justify action: ‘care must be taken where evil doesn’t outweigh the possible benefits (Begby et al (2006b), Page 325).’ This is further supported by Frowe who explains it is lawful to unintentionally kill, whenever the combatant has full knowledge of his actions and seeks to complete his aim, but it would come at a cost. However, this does not hide the fact the unintended still killed innocent people, showing immorality in their actions. Thus, it depends again on proportionality as Thomson argues (Frowe (2011), Page 141).

This leads to question of what qualifies to be a combatant, and whether it is lawful to kill each other as combatants. Combatants are people who are involved directly or indirectly with the war and it is lawful to kill ‘to shelter the innocent from harm…punish evildoers (Begby et al (2006b), Page 290).However, as mentioned above civilian cannot be harmed, showing combatants as the only legitimate targets, another conditi