My 9 year old brother is tearing my family apart...?

I really don't know what to do anymore.

My little brother is 9 (I am 16) and he is, in the most blunt way possible, a TERRIBLE child...

Now you may think I'm exaggerating, but bear with me for a bit--

Just a few moments ago, I was sitting in my room doing my homework. I then hear my brother screaming (screaming being the exact term for it, none of that whining or nagging business), so I walk out to see whats going on. I see my mother awake, (she is usually sleeping at this point because she works the night shift) and I'm perplexed at that point. My little brother then yells, "I want to eat!" My father is in his room, my guess is that he's trying to ignore it for as long as he can. I tell him to stop, and he does stop for a moment -- however, he then yells yet again, "I want to eat!"

It is around 930PM; earlier when he was about to eat dinner he threw yet another temper tantrum, absolutely REFUSING to eat his vegetables. Of course, my mother gave in -- so he ate a bit of it and left the vegetables untouched.

My mom then got angry at him for 1. waking her up, 2. wanting food when she offered him dinner and refused to eat it. (Could someone explain to me how a conscience is developed in a child? I have taken psychology and there are theories, but I am curious... when/if he will ever develop one)

So at that point my dad comes out, and I tell my mother to go back to her room to go get some sleep. He then starts his hissy-fit all over again. What really got me angry was the fact that, despite the fact that he is like this all (ALL) the time, my father still pampers him yet complains about what a bad child he is. My father recently got him a Nintendo DSi, (why? because he asked for one. that's why.) and my little brother 'promised' to be good in exchange for it.

So then my dad goes, "If you don't stop, I'll cancel your order for the DS" and this only proceeds to make him more agitated. However, as this continues on, my brother then goes "I'll stop crying if you don't return my DS!"

My father has conditioned him to the point where my brother is the one doing the negotiating and setting the rules, not my dad. And this is how it goes /every time/. And you know what's worse--it works... /every time/. No matter how much my parents complain about his behavior, they don't do anything to change it. They complain about it, when it was their doing in the first place.

After he settles down and goes off to take a shower, I confront (angrily, i will admit) my dad about how my brother will never learn if he continues to 'discipline' him like this. He then asks me, "then what am I supposed to do?"

That broke my heart.

It made me angry that my parents don't even have the slightest clue on how to discipline him, and the fact that he's asking /me/ for help. I am not his parent, I told him. I may tell him to do things but he doesn't listen to me (ever) because I am not seen as an authority figure to him. But yet, my parents expect me to be the one to discipline him...

and now I feel like theres been this huge weight that's been put on my shoulders, like every time my brother acts up it's my fault that he's not behaving the way he should be...

Actually, I don't really know what I'm asking for right now -- help with my brother's behavior, or help with preventing myself from completely breaking...