Original sentence: While it is clear that Ngo Dinh Diem was initially the favored candidate of the United States to rule South Vietnam, he later displayed a sufficiently independent and nationalistic streak that the American government assented to his removal by a coup
Edited sentence: While it is clear that Ngo Dinh Diem was initially the favored candidate of the United States to rule South Vietnam, he later displayed a sufficiently independent and nationalistic (and incompetent) streak that the American government assented to his removal by a coup