In 1879. president rutherford b. hayes had the first telephone installed in the white house, but it was rarely used because

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.

this is a good question! i'll do some research and come back when i have the answer!