So let's say you are the ruler of a Great House of the Lansraad, no? One day the emperor, who rules over the Atreides and Harkonnens alike, decides to give Arrakis to the Atreides. All good. But then, literally the same month, the Harkonnens kill the entire Atreides bloodline and destroy a Great House in the process.

What will the emperor do! How will he punish the Harkonnen who, again, are under the rule of the Imperium??…

What do you mean he did NOTHING? Nothing at all? A Great House has been slain, is this not a crime? A serious one? …

Am i missing something here? Did these Great Houses be ok with the Atreides Dying? Because they are supposed to be popular, almost as popular as the emperor, as i understand, at least popular enough for him to be jealous.

I would get this if it happend under different governments like on earth, not every country has the capability or even the interest to help countries under war, but they don't have to because they are independent countries under their own rules and governments, But in the Empire?? Dune's Emperor Shaddam the IV is literally known as Emperor of the Known Universe. If i was a Great House living in the time of the Atreides genocide i would believe that either the Emperor was in on it, or that his ruling is utterly and entierly useless, like how we regard the ONU in real life.

Edit: I know it was the emperor who set it all up and used his Sardaukar Army to kill the Atreides, but what i mean to emply is that this was not common knowledge among the Great Houses and they would have seen it as a Harkonnen-led Genocide.