In the following excerpt of "Sinews of Peace", it is stated that the United Nations Organization's primary purpose is to prevent war. Maintaining peace was a common goal of many countries after World War II, so the UN was a way of engaging the countries cooperatively for preventing war.
"A world organisation has already been erected for the prime purpose of preventing war, UNO, the successor of the League of Nations, with the decisive addition of the United States and all that that means, is already at work. We must make sure that its work is fruitful, that it is a reality and not a sham, that it is a force for action, and not merely a frothing of words, that it is a true temple of peace in which the shields of many nations can some day be hung up, and not merely a cockpit in a Tower of Babel. Before we cast away the solid assurances of national armaments for self-preservation we must be certain that our temple is built, not upon shifting sands or quagmires, but upon the rock. Anyone can see with his eyes open that our path will be difficult and also long, but if we persevere together as we did in the two world wars-though not, alas, in the interval between them-I cannot doubt that we shall achieve our common purpose in the end."