The United Nations is the world’s largest international organisation. 

The reasons for the establishment of the United Nations are:

(i) Two World Wars were fought at the beginning of the twentieth century. 

(ii) Life and property were destroyed on a large scale in these wars. 

(iii) As a result, the League of Nations was established after the First World War and the United Nations was established after the Second World War out of a realisation that there has to be a mechanism to establish world peace. 

(iv) The League of Nations did not succeed at all. 

(v) But after the use of the nuclear weapons in the . Second World War, the idea took root that such destructive wars should be stopped and that it is the collective responsibility of all nations to do so. 

(vi) The United Nations was established after the Second World War to instill this understanding among all nations. 

(vii) Hence, the United Nations, an international organisation was established to ensure peace and security at the international level