All the heart of the league of nations covenant was

 The commitment to collective security.

Explanation:  That shared commitment to international security and peace was expressed in Article X of the League of Nations charter:

In addition to the overall goal of collective security, the League of Nations established as its aims disarmament across nations, settling disputes between countries through negotiation, and improving welfare of people around the globe.  (The UN today has similar goals.)

the right answer is the end of world war ii

after the end of a global wwii all the nations involved, in an attempt to create an organization to maintain world peace. this agreement would work settling international disputes via negotiation and arbitration instead of leading the issues escalate to another war.

a variant spelling of the word dote (british)