Why did other world leaders think that Stalin had gone crazy?

It was because he was a cruel tyrant who killed millions of people.

Explanation:

Accroding to a 2012 article by Russian Beyond, 60% of Russians had "incompatible images of Stalin in their heads"

the influence of charles louis de secondant , baton montesquieu.

the monroe doctrine is the best known u.s. policy toward the western hemisphere. buried in a routine annual message delivered to congress by president james monroe in december 1823, the doctrine warns european nations that the united states would not tolerate further colonization or puppet monarchs.