The Cold War’s denouement not only saw profound political changes throughout Eurasia, but an unprecedented power shift resulting from the Soviet Union’s decline that ultimately ushered in the United States’ “unipolar era.” Nevertheless, the United States’ response to the late Cold War power shift remains underexplored. This chapter fills the gap by examining the processes by which the United States recognized the power shift underway and adapted its foreign policy. I make three arguments. First, American policymakers in the Reagan and George H. W. Bush administrations acknowledged that Soviet decline rebounded to the United States’ geopolitical advantage. Second, American policymakers responded by exploiting Soviet problems, driven by recognition that Soviet decline allowed for American gains, yet worried that the window for gains would soon close. Third, this effort altered European security, as the United States undercut the Soviet Union as a challenger while fostering conditions that could allow it to dominate European security irrespective of whether Soviet problems continued. Put simply, the United States used the Soviet decline to reify American advantages in Europe, garnering oversight over a region that had long been the cockpit of geopolitical contestation. The result meant that unipolarity also translated into American near-hegemony in Europe.