  The experimental and theoretical evidence relating spin dependence and long
range confinement is reviewed. One of the simplest confinement ideas, the
dynamic electric flux tube picture of Buchm\"uller, can be exploited to yield a
complete effective Hamiltonian. In addition to pure Thomas spin-orbit splitting
the other relativistic corrections are calculated. It is shown that our
effective Hamiltonian is identical to the mechanical relativistic flux tube
model and gives relativistic corrections in agreement with QCD predictions.
