The ironic thing about all this intervention is that it frequently fails to achieve American objectives. Often the newly installed dictator grows comfortable with the security apparatus the CIA has built for him. He becomes an expert at running a police state. And because the dictator knows he cannot be overthrown, he becomes independent and defiant of Washington's will. The CIA then finds it cannot overthrow him, because the police and military are under the dictator's control, afraid to cooperate with American spies for fear of torture and execution. The only two options for the U.S at this point are impotence or war. Examples of this "boomerang effect" include the Shah of Iran, General Noriega and Saddam Hussein. The boomerang effect also explains why the CIA has proven highly successful at overthrowing democracies, but a wretched failure at overthrowing dictatorships.