Final answer:
Peter the Great's reforms resulted in the weakening of traditional privileges of Russian nobles, as they were coerced into state service to help modernize and westernize Russia.
Step-by-step explanation:
According to Vasili Klyuchevsky, one effect Peter the Great's reforms had on the Russian nobles was the weakening of their traditional privileges and the forcing of them into service to the state. Peter's desire to modernize Russia and westernize its institutions meant that the landowning nobles' power was reduced as they were required to serve in military or civil positions. Additionally, the reforms aimed to create a more efficient and centralized government, which often went against the nobles' interests who were accustomed to autonomous control over their lands and serfs.