Came to prominence during and immediately after World War I, partly as a reaction against the perceived failings of the balance of power system. The concept's best-known early advocate was Woodrow Wilson. Appalled by the outbreak of war in Europe, Wilson decided by the end of 1914 that nations must be “bound together for the protection of the integrity of each, so that any one nation breaking from this bond will bring upon herself war; that is to say punishment, automatically”. He called for a League to Enforce Peace, and publicly committed himself to “an association of nations”. In his famous 1917 “peace without victory” speech to the U.S. Senate calling for war against Germany, Wilson lashed out at the “crude machinations” of the balance of power and its failure to keep the peace in Europe. He pledged that once the war was over, he would work to replace the balance of power with a “community of power.” It was this idea which would eventually grow into the modern notion of collective security and lead to the creation of the ill-fated League of Nations.

While the United States turned its back on collective security when it rejected participation in the League, the idea resurfaced under President Roosevelt. In 1943, Cordell Hull, one of the architects of the successor to the League, the United Nations, declared that the creation of an international collective security organization meant there would be “no need for spheres of influence, for balance of power, or any other of the special arrangements through which, in the unhappy past, the nations strove to safeguard their security.” Speaking to the Senate following the 1945 San Francisco conference, Senator Arthur Vandenberg declared that he would support ratification of the United Nations Charter, saying “peace must not be cheated of its collective chance … We must have collective security to stop the next war, if possible before it starts; and we must have collective security to crush it swiftly if it starts; and we must have collective action to crush it swiftly if it starts in spite of our organized precautions.”