dual/single vertical stabilizer

[boeing boeing.. gone]

Hi all,

I have been having a look around for data on the above... specifically, why would you design a fighter with a single stablizer over a dual stabilizer fin.

The american and russian fighters seem to utilise a dual stabilizer design (on the whole except the F16) where as the european designers seem to go for a single stabilizer design????

if anyone can shed some light it would be appreciated

thanks