In 1972, President Nixon began a process to normalize relations with communist China. In his own stumbling-into-stuff-way, President Reagan did the same with the Soviets in the 1980s. Both countries were powerful and in a position to really challenge the United States. When all these changes happened, having two Republican presidents reach out to Cold War enemies wasn’t really an issue.
Then there is Cuba. The Caribbean nation has posed no real threat to U.S. hegemony, be it in economic or military terms.
Why then has the U.S. boycott against Cuba lasted for more than five decades?