Legitimate War

Source: Compendium of the Social Doctrine of The Church ©

500. A war of aggression is intrinsically immoral. In the tragic case where such a war breaks out, leaders of the State that has been attacked have the right and the duty to organize a defence even using the force of arms.[1049] To be licit, the use of force must correspond to certain strict conditions: “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 modern 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”.[1050 ]

If this responsibility justifies the possession of sufficient means to exercise this right to defence, States still have the obligation to do everything possible “to ensure that the conditions of peace exist, not only within their own territory but throughout the world”.[1051] It is important to remember that “it is one thing to wage a war of self-defence; it is quite another to seek to impose domination on another nation. The possession of war potential does not justify the use of force for political or military objectives. Nor does the mere fact that war has unfortunately broken out mean that all is fair between the warring parties”.[1052]

501. The Charter of the United Nations, born from the tragedy of the Second World War with the intention of preserving future generations from the scourge of war, is based on a generalized prohibition of a recourse to force to resolve disputes between States, with the exception of two cases: legitimate defence and measures taken by the Security Council within the area of its responsibilities for maintaining peace. In every case, exercising the right to self-defence must respect “the traditional limits of necessity and proportionality”.[1053]

Therefore, engaging in a preventive war without clear proof that an attack is imminent cannot fail to raise serious moral and juridical questions. International legitimacy for the use of armed force, on the basis of rigorous assessment and with well-founded motivations, can only be given by the decision of a competent body that identifies specific situations as threats to peace and authorizes an intrusion into the sphere of autonomy usually reserved to a State.

b. Defending peace

502. The requirements of legitimate defence justify the existence in States of armed forces, the activity of which should be at the service of peace. Those who defend the security and freedom of a country, in such a spirit, make an authentic contribution to peace.[1054] Everyone who serves in the armed forces is concretely called to defend good, truth and justice in the world. Many are those who, in such circumstances, have sacrificed their lives for these values and in defence of innocent lives. Very significant in this regard is the increasing number of military personnel serving in multinational forces on humanitarian or peace-keeping missions promoted by the United Nations.[1055]

503. Every member of the armed forces is morally obliged to resist orders that call for perpetrating crimes against the law of nations and the universal principles of this law.[1056] Military personnel remain fully responsible for the acts they commit in violation of the rights of individuals and peoples, or of the norms of international humanitarian law. Such acts cannot be justified by claiming obedience to the orders of superiors.

Conscientious objectors who, out of principle, refuse military service in those cases where it is obligatory because their conscience rejects any kind of recourse to the use of force or because they are opposed to the participation in a particular conflict, must be open to accepting alternative forms of service. “It seems just that laws should make humane provision for the case of conscientious objectors who refuse to carry arms, provided they accept some other form of community service”.[1057]

c. The duty to protect the innocent

504. The right to use force for purposes of legitimate defence is associated with the duty to protect and help innocent victims who are not able to defend themselves from acts of aggression. In modern conflicts, which are often within a State, the precepts of international humanitarian law must be fully respected. Far too often, the civilian population is hit and at times even becomes a target of war. In some cases, they are brutally massacred or taken from their homes and land by forced transfers, under the guise of “ethnic cleansing”,[1058] which is always unacceptable. In such tragic circumstances, humanitarian aid must reach the civilian population and must never be used to influence those receiving it; the good of the human person must take precedence over the interests of the parties to the conflict.

505. The principle of humanity inscribed in the conscience of every person and all peoples includes the obligation to protect civil populations from the effects of war. “That minimum protection of the dignity of every person, guaranteed by international humanitarian law, is all too often violated in the name of military or political demands which should never prevail over the value of the human person. Today we are aware of the need to find a new consensus on humanitarian principles and to reinforce their foundation to prevent the recurrence of atrocities and abuse”.[1059]