Dog eat cat
And yet the writers often think quite short term with these differing cultures and introduce elements that really make no sense in context. There was the early episode of DS9 where education and basic literacy were considered a waste of time to the most acquisitive species in the galaxy, as it hadn't occured to them (or at least to the writer) that knowledge is power.
A consideration of the warrior culture of the Klingons doesn't bear much examination, either. The driving credo that it is shameful for a Klingon not to die in battle might work for a small hunter/gatherer culture of northern Europe where every fit male was by definition a warrior, but in an interplanetary culture (particularly one that practices sexual equality) the majority would be working in support services, and never get the opportunity to fight a battle, let alone die in one.
But don't all klingons aspire to the same ideals? You are left with an image where every hair stylist and checkout girl is just looking for an excuse to face mortal danger. Every restaurant serves blowfish as standard because of the risk factor and childrens' toys are only rejected if they don't have spiky bits. But would you want every bus driver or postal worker to be thinking "Today is a good day to die"? It would surely have to lead to a very tense society.
And as for the whole concept of promotion by assassination, it may have some merit in assuring that those in charge are the fittest and strongest, but they must also be the most paranoid.
There's a great Jonah Hex story about a girl who goes around picking fights with famous gunslingers. They don't take her seriously so she shoots them and claims it was a fair fight because she had called them out. Which all works fine and dandy until she tries it on Jonah, and of course he does take it seriously and blows her head off.
But back to Klingon society. You'd think there might be some basic etiquette about when it was appropriate to assassinate the boss. Like it would be bad form during a mission to stab him in the back unless he was actually incompetent. It must be hard to get anything done when the guys you are leading are as much of a threat as the enemy.