The ‘Reign of Terror’ happened with the killings of political opponents in France as a result of internal chaos and civil war during the French Revolution.
The American Revolution was easier to complete as compared to the French Revolution as the former was occurring in a different continent without intervention from European states and free from the troubles of war. Contrary to that, the French revolution was made difficult with the presence of all the said factors.
The challenge of internal chaos and civil war had the greatest impact on the inability of French Revolutionaries to complete a successful revolution. This challenge divided them internally and instead of making the revolution successful they indulged in fighting against each other.
The strength of unity among the American revolutionaries had the greatest impact on their ability to complete a successful revolution. Unity of the American people kept them focused towards their goal and helped them to give up political differences.