Final answer:
The Soviet Union collapsed in 1991, ending the Cold War and leaving the US as the only remaining military superpower. The fall of the USSR was prefaced by failed reforms and attempts to maintain its grip on satellite states and its own republics. The US emerged as a dominant global power, influencing the world's political and economic systems.
Step-by-step explanation:
The Soviet Union collapsed in 1991 leaving the US as the only remaining military superpower. This event marked the end of the Cold War, an era spanning from the end of World War II to the dissolution of the USSR, where the world was largely divided between two opposing ideological blocs: Communist Soviet Union and the capitalist United States. With the Soviet Union gone, many believed that the spread of liberal democracy and capitalism would prevail worldwide, a concept famously theorized by political scientist Francis as 'The End of History.'
During the late 1980s, under the leadership of Mikhail Gorbachev, the Soviet Union attempted reforms with perestroika (restructuring) and glasnost (openness) but ultimately failed to rejuvenate the struggling nation. The 1991 coup attempt by Communist Party hardliners against Gorbachev signaled the irreversible decline of the Soviet Union. The subsequent liberation movements within its own republics and its inability to maintain control over satellite states led to its formal dissolution on December 31, 1991. The United States, having emerged more economically and militarily robust, became the dominant global power, steering the post-Cold War world order.