Siamese kitten attacking my other cat

We recently adopted a Siamese kitten and we already have a 3 year old black short hair. Both are neutered and front declawed (please don't give me the I'm holier then thou lesson about declawing; I've had it a thousand times). The black cat has been with us since he was a kitten and he's the sweetest cat; his nickname is "the snuggle" for a reason. His name is Buddy. The Siamese is named Taz (hint hint).

Here's the problem. We did the proper introduction. Taz stayed in my mom's room for a week before we gradually started opening the door a tiny bit so they could smell each other. We tried feeding them on each side of the door but Buddy doesn't want any of it. We let each cat out to run around the house while the other stays locked in their safe room. Taz has finally mellowed out with the other members of the family and he is a really nice cat now. BUT, when ever we try and let the 2 cats actually free roam face to face, Taz attacks Buddy. VICIOUSLY. Buddy simply runs away now at the sight of Taz and it triggers an attack if he can't get to a safe spot where Taz can't get him. I've tried disciplining Taz (saying no etc.) and I immediately grab him and put him away when he attacks and he's learned not to attack Buddy in my presence. If I'm in my room, Buddy sits on my dresser while Taz sits on the bed and they won't go at it. Buddy tries to go find Taz and get acquainted, but Taz simply attacks. Buddy is starting to fight back more and it's slowly changing his behavior. He's VERY anxious and throwing up more and more.

Sorry for the long winded post, but I wanted to be as accurate as possible. We love both cats dearly but are at our wits end because we simply can't leave them out together.

Anyone have any ideas? Thanks very much!

Drew

Thanks. Perhaps I came across as a bit harsh with my de-clawing comment. My apologies.

I'm starting to think this is the problem: my older black short hair has, to my knowledge, never been exposed to other cats since we found him. We almost ran him over on a street so I grabbed him - this was in late October 3 years ago. I thought it was a sign from a higher power; we rescued a black kitten near Halloween! So he doesn't know how to and simply will not fight back and defend himself from the vicious attacks from the Siamese kitten. When Buddy (the older cat) runs away, it triggers Taz to chase him and attack.

From my reading, Siamese cats are fairly aggressive and territorial.