The policy of regime change, in which a non-democratic or otherwise hostile foreign government is forcibly ousted, often fails. As the Cato Institute points out, there are a number of reasons why. Forcible overthrows rarely accomplish the desired goals, such as spreading democracy or advancing economic interests. And they almost always lead to destabilization and other long-term problems.
This is especially true when an intervention is aimed at countries that have a large military or that are highly repressive. The US-backed overthrow of Mohammad Mosaddegh in 1953, for example, sowed the seeds for today’s extremist Iran. The US’s attempt to overthrow Jacobo Arbenz in 1954, and its Bay of Pigs failure in 1961, created a climate of resentment that helped birth Fidel Castro.
Even when a forcible overthrow does succeed, it doesn’t guarantee that democracy will take hold or that the target country will align with US interests. It may instead become an authoritarian, anti-US government that poses a threat to regional stability and global peace.
Many of the problems with regime change stem from cognitive biases that make policymakers focus too much on the desirability of a goal, and not enough on how hard it will be to achieve. Policymakers often have a difficult time confronting the reality that achieving their objectives will likely require a lengthy institution-building mission that could end up costing the US a lot of money. In addition, they often forget that the target country has its own priorities and that changing those priorities will not necessarily benefit American interests.