The political leader known for his role in the fall of the Soviet Union is Mikhail Gorbachev. His policies of glasnost (openness) and perestroika (restructuring) aimed to revitalize the Soviet economy and improve transparency but eventually led to the unraveling of the Soviet system. Gorbachev's attempts at reforms drew criticism from hardliners and contributed to the rise of nationalist movements within the republics. His leadership during a critical period in history facilitated the end of the Cold War and transitioned Eastern Europe towards greater democracy and market economies, leaving a lasting impact on global politics.