There is many reasons why the United Nations was formed. Some of the reasons were to maintain international peace and security, and to take effective measures for the prevention and removal of threats to the peace. Also, for the acts of aggression or other sources of the peace, and to bring about by peaceful means in conformity with the principles of justice and international law.
Another reason Was to develop friendly relations among nations based on respect for the principle of equal rights and self-determination of people and to take other appropriate measures to strengthen universal peace.
The last reason is to achieve international co-operation in solving international problems of an economic, social, cultural, or humanitarian character, and in promoting and encouraging respect for human rights for fundamental freedoms for race, sex, language, or religion.
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https://www.quora.com/What-are-the-reasons-the-United-Nations-were-formed