For Aquinas there are 5 conditions for a just war: (1) the conflict must be just e.g. to save the lives of civilians (2) the conflict must be declared by a legitiamte authority. e.g. a government (3) there must be a likelihood of success (4) The response must be proportionate to the cause and you must use no more force than is necessary. (5) All other options (e.g. diplomacy) must have failed. Any analysis of a conflict saying why either all of these conditions are filled or a more extensive analysis as to why one of them fails.