Final answer:
Robespierre initiated a policy of terror to defend republican ideals against various threats during the turbulent time of the French Revolution, which led to mass executions and the use of the guillotine as a symbol of the era. The Reign of Terror eventually led to Robespierre's downfall and the rise of the Directory.
Step-by-step explanation:
Maximilien Robespierre believed it was necessary to initiate a policy of terror because he saw it as a mechanism to enforce and protect republican ideals in a period of profound turmoil. During the Reign of Terror, France faced internal and external threats, such as counterrevolutionaries, émigrés intending to disrupt the republic, and European nations aiming to end the revolutionary government. Robespierre and the Committee of Public Safety, therefore, used terror to swiftly eliminate those who they perceived as enemies of the revolution. The Laws of Suspects led to mass imprisonments, and the guillotine became the symbol of this ruthless campaign against accused enemies, including prominent figures like Georges Danton and Marie Antoinette. Despite intentions to preserve the revolution, the Reign of Terror ultimately resulted in Robespierre's own downfall and execution, signaling the end of this violent chapter and leading to the establishment of the more moderate Directory.