During the Eisenhower administration the CIA created a project code named ZR/RIFLE that was responsible for "wet operations," i.e. assassinations of double agents and foreign leaders. The most famous of the ZR/RIFLE endeavors were the many intricate and absurd plots to kill Fidel Castro.
The success rate of ZR/RIFLE projects was pretty low, because the huge administrative task of covering the CIA's tracks diverted time and energy away from actually killing people. This is why the KGB was a much more successful intelligence organization. If the Soviets wanted someone dead they just killed him and then buried the evidence. Secret operations are much easier in a police state since the flow of information is strictly controlled anyway.
The CIA suffered from a schizoid personality. It's stated mission was to defend the American ideals of freedom and democracy and yet the very nature of it's work necessitated the most secretive and repressive measures. The KGB suffered no such conflicts of conscience, making it the far more formidable agency.
We can see now that the lack of foresight and self-critique that plagues the current CIA is nothing new, and is in fact an institutional dilemma - just as there is a shortage of Arabic-speaking agents today, the covert operators in Cold War Berlin and Cuba were startlingly deficient in Russian and Spanish. It is an American disorder. We seek to manipulate the world without bothering to take the time to understand it. I suspect your typical Islamic zealot suffers from a similar myopia. I'm not sure if this is a good or bad thing.