It is a truth that tyrants breed incompetents. In fact, it is a necessity. To work for a tyrant requires several things. It first requires a lack of basic humanity. There are many without the moral fiber to develop ethics, and they run the gamut of intelligence. Yet it is a fact that geniuses who lack a strong ethical base are very dangerous human beings. Charles Manson, Joseph Goebbels, Richard Nixon, these humans leave devastation and disaster in their wake. Although useful to a tyrant at the high levels, they are antithical to the unthinking, unquestioning authority tyrants seek to establish. Thus, they are left with the remainder, the stupid, incompetent, or naive and deceived.
This explains why time and again tyrannical states have missed enormous, obvious truths, truths. The Japanese never noticed the fact that the Americans had broken their codes, despite the Americans blatantly showing off the fact by shooting down Yamamoto's plane - the only messenger plane they shot down, and one that the Americans shouldn't have known was even in the air. The French Monarchy missed the fact that the entire country was on the brink of armed revolt. And the Iraqi army thought it would have a shot at taking and holding Kuwait.
This is the great advantage of revolutionaries, and something that tyrants never factor in. Time and again they rely on their secret police, their network of infiltrators, their spies and their armies, never realizing that they are missing the essential component, the intelligence at ground level, that makes those institutions function so well for free and open countries.
The mission has succeeded
