Final answer:
Wilson's belief in the united force of the world's nations for peace is supported by promoting collective responsibility and collective security through the League of Nations.
Step-by-step explanation:
Woodrow Wilson's belief in the united force of the world's nations as the best hope for peace is supported because it promotes a collective responsibility, preventing any single nation from wielding excessive power. This idea is reflected in the concept of collective security, where countries enter into agreements to defend each other against military threats. By fostering cooperation and mutual guarantees of political independence, the League of Nations, proposed by Wilson, aimed to prevent aggression and maintain peace among nations.