Hitler knew the internal dangers to his Third Reich, so he created a bodyguard of young Germans yearning to serve the state in any capacity, for his protection. They were the SD, the SA, and, in turn, the SS, whose job it was to oversee policing, intelligence, and operate the death camp system in Nazi Germany. Our knowledge of these organizations is not lacking. If we look closely, we can see the faint but alarming outline of a totalitarian police state, rising like the SS of Nazi Germany here in America, operating independently, without fear, under the auspices of the Deep State, not the US Congress or the Constitution.
Intelligence has many facets, and keeping a leash on what information is disseminated or not up to leadership, what is essential and what is not, what is happening in other countries, and how their actions affect the US is the primary role of government Intelligence agencies. During the Cold War, intelligence was directed at protecting our military-industrial secrets from the Soviet bloc nations like Poland, East Germany, and others. Then the Soviet Union collapsed, and for a decade or so, we have idled along without a main enemy to confront but still spending wads of money, not on military stuff, but silly social programs to entrap Americans to government handouts further while ignoring China and North Korea militarism lurking on the horizon. Our Vietnam experience, a war we chose not to win, exhausted the patience of Americans' support, opening the door for Marxist-style radicalism to infiltrate our schools and start the process of reforming the minds of American children to think in terms of collectivism. Then 9/11 happened, and for a short while, Americans came together again to face an unsuspected but new common enemy, Radical Islam.