Youcat commented through CCC – Question n. 398.

YOUCAT Question n. 398 - Must Christians be pacifists?

(Youcat answer) The Church strives for peace but does not preach radical pacifism. Indeed, no one can deny either the individual citizen or particular governments and alliances the fundamental right of armed self-defense. War is morally justifiable only as a last resort.

A deepening through CCC

(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).     

Reflecting and meditating 

(Youcat comment) The Church unmistakably says No to war. Christians should do everything possible to avoid war before it starts: They oppose the stockpiling of arms and trafficking in weapons; they fight against racial, ethnic, and religious discrimination; they work to put an end to economic and social injustice and thus promote peace.   

(CCC Comment)

(CCC 2304) Respect for and development of human life require peace. Peace is not merely the absence of war, and it is not limited to maintaining a balance of powers between adversaries. Peace cannot be attained on earth without safeguarding the goods of persons, free communication among men, respect for the dignity of persons and peoples, and the assiduous practice of fraternity. Peace is "the tranquillity of order" (St. Augustine, De civ. Dei, 19, 13, 1: PL 41, 640). Peace is the work of justice and the effect of charity  (Cf. Isa 32:17; cf. GS 78  §§ 1-2).    

(The next question is: When is the use of military force allowed?)