Final answer:
Ronald Reagan is the U.S. president most strongly associated with the collapse of the Soviet Union due to his aggressive anti-communist policies and military spending, which were key factors in the eventual dissolution of the Soviet state.
Step-by-step explanation:
The U.S. president most closely associated with the collapse of the Soviet Union is Ronald Reagan.
The U.S. president most associated with the collapse of the Soviet Union is Ronald Reagan (A).
Reagan considered the Soviet Union an "evil empire" and vigorously pursued policies aimed at ending communism. He advocated for negotiations with the Soviets, albeit from a position of strength, which led to a significant increase in the United States' military spending. This, coupled with the Soviet's own economic challenges and the costly war in Afghanistan, contributed to the USSR's weakening. Mikhail Gorbachev's initiatives like 'glasnost' and 'perestroika' aimed to reform the Soviet system, but ultimately it was unable to keep pace with the changes, leading to the dissolution of the Soviet Union in 1991. President George H.W. Bush, Reagan's successor, continued with Reagan's policies and even signed the START treaty with Gorbachev, but it is Reagan's tenure that is most prominently linked with the end of the Cold War and the collapse of the Soviet Union.