What actions might the United States have justified by the domino theory?

Plz ? ? 20 points for this question ! hhjc6

Diarys letters and memoirs are good examples of what

What was unification difficult to accomplish in both germany and italy? a.) weaker states we’re attacked by stronger states for control of the emerging nations. b.) major european powers fought to keep independent states under their control. c.) germans and italians did not share common histories and languages.