What do you do when feline harmony is disrupted?

I have 3 cats; Zoe (female calico 7 yrs old 9lbs spayed and declawed), Roo (male siamese mix 6 yrs old 18-20lbs muscular neutered), and Tiger (male siamese mix 5 yrs old 20 lbs not so muscular neutered). The history is that they have all been together for the last 5 years since Tiger was a kitten. He has always been somewhat of a bully but there has always been a relative peace between the 3 of them. He and Roo have always seemed to be very close, cuddling and bathing each other whereas Zoe tends to keep to herself more often than not. Over the past two months Tiger's bullying of Roo has disrupted our previously peaceful feline family. Now whenever Tiger comes into a room Roo will growl. Roo will also chase me into my bedroom with a great deal of desperation when I come home. As well, he has resorted to hiding in bedrooms when we try to leave the house. I'm willing to declaw the boys but would rather not. Short of finding Tiger a new home, does anyone have any suggestions?