The delusions of the era -- not much different from today.
The film was meant to put across an idea which, at that time, was extremely popular among journalists and commentators on U.S. foreign policy. This was the notion that the charismatic "leaders" who were emerging in third world countries were honest patriots who were "pushed into the arms of the Communists" by the follies of American foreign policy.
In retrospect, this idea is demonstrable nonsense.
Not that this excuses the sleazy policy of promoting dictatorships that American politicians delighted in then (and now).
The film shows both a naive belief in the "good intentions" of American foreign policy (which was in fact driven by corporate interests and scheming sleezeballs), and a naive belief in the nobility of these charismatic "post-colonial" messiahs, who all eventually revealed themselves to be nothing more than gangsters.