The Catechism talks about World Peace

1909 Finally, the common good requires peace, that is, the stability and security of a just order. It presupposes that authority should ensure by morally acceptable means the security of society and its members. It is the basis of the right to legitimate personal and collective defense.
 

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." Peace is the work of justice and the effect of charity.
 

2305 Earthly peace is the image and fruit of the peace of Christ, the messianic "Prince of Peace." By the blood of his Cross, "in his own person he killed the hostility," he reconciled men with God and made his Church the sacrament of the unity of the human race and of its union with God. "He is our peace." He has declared: "Blessed are the peacemakers."

2306 Those who renounce violence and bloodshed and, in order to safeguard human rights, make use of those means of defense available to the weakest, bear witness to evangelical charity, provided they do so without harming the rights and obligations of other men and societies. They bear legitimate witness to the gravity of the physical and moral risks of recourse to violence, with all its destruction and death.
 

2315 The accumulation of arms strikes many as a paradoxically suitable way of deterring potential adversaries from war. They see it as the most effective means of ensuring peace among nations. This method of deterrence gives rise to strong moral reservations. The arms race does not ensure peace. Far from eliminating the causes of war, it risks aggravating them. Spending enormous sums to produce ever new types of weapons impedes efforts to aid needy populations; it thwarts the development of peoples. Over-armament multiplies reasons for conflict and increases the danger of escalation.
 

2317 Injustice, excessive economic or social inequalities, envy, distrust, and pride raging among men and nations constantly threaten peace and cause wars. Everything done to overcome these disorders contributes to building up peace and avoiding war:

Insofar as men are sinners, the threat of war hangs over them and will so continue until Christ comes again; but insofar as they can vanquish sin by coming together in charity, violence itself will be vanquished and these words will be fulfilled: "they shall beat their swords into plowshares, and their spears into pruning hooks; nation shall not lift up sword against nation, neither shall they learn war any more."