That irony though.
Where exactly is the irony? Perhaps you need a dictionary.
So what's the answer? CIA, FBI, NSA, or what?
I'm stupid some dumb it down for me. You said it's not a difficult question. So tell me which alphabet soup agency is responsible for this.
Lol. When people say the govt. was behind 9/11, for example, I doubt many people actually believe the senators and congressmen sat around and hatched out a plan. It's not like every single employee of the FBI or CIA is in the know when when a few conspire to commit crimes. "The govt. did it" is a convenient way to deflect responsibility away from named individuals committing actual crimes.
As you stated, the "govt." is multifaceted and incapable of maintaining a single agenda or set of agendas across the board. What people are generally referring to, since you want to play dense, is a network of wealthy elite with an expansive reach which may include public employees.
So for example, a conglomerate of defense contractors known as The Carlyle Group profits during times of war. That is their agenda. Now when a key member of this network of businessmen is a former CIA official, former US President with a son currently presiding you can see how private interests can become intertwined with government conspiracy.
Another example, the former CEO of the worlds most powerful investment bank being the architect of the govt's bailout of financial institutions.
How many Rockefeller's are politicians? How many Harriman's? Bush's?
It's less about govt entities being wholly corrupted and criminal and more about individuals with a seat in power having conflicts of interest with those they are elected to represent.