483. When is it morally permitted to use military force?

483. When is it morally permitted to use military force?   

(Comp 483) The use of military force is morally justified when the following conditions are simultaneously present: * the suffering inflicted by the aggressor must be lasting, grave and certain; * all other peaceful means must have been shown to be ineffective; * there are well founded prospects of success; * the use of arms, especially given the power of modern weapons of mass destruction, must not produce evils graver than the evil to be eliminated.

“In brief”

(CCC 2328) The Church and human reason assert the permanent validity of the moral law during armed conflicts. Practices deliberately contrary to the law of nations and to its universal principles are crimes.   

To deepen and explain

(CCC 2307) The fifth commandment forbids the intentional destruction of human life. Because of the evils and injustices that accompany all war, the Church insistently urges everyone to prayer and to action so that the divine Goodness may free us from the ancient bondage of war (Cf. GS 81 § 4). (CCC 2308) All citizens and all governments are obliged to work for the avoidance of war. However, "as long as the danger of war persists and there is no international authority with the necessary competence and power, governments cannot be denied the right of lawful self-defense, once all peace efforts have failed" (GS 79 § 4).      

Reflection

(CCC 2309) The strict conditions for legitimate defense by military force require rigorous consideration. The gravity of such a decision makes it subject to rigorous conditions of moral legitimacy. At one and the same time: - the damage inflicted by the aggressor on the nation or community of nations must be lasting, grave, and certain; - all other means of putting an end to it must have been shown to be impractical or ineffective; - there must be serious prospects of success; - the use of arms must not produce evils and disorders graver than the evil to be eliminated. The power of modem means of destruction weighs very heavily in evaluating this condition. These are the traditional elements enumerated in what is called the "just war" doctrine. The evaluation of these conditions for moral legitimacy belongs to the prudential judgment of those who have responsibility for the common good.

(Next question: In danger of war, who has the responsibility for the rigorous evaluation of these conditions?)