  The formalism of two coupled Dirac equations within constraint instant form
dynamics is used to study the nucleon-nucleon interaction. The salient features
and the final Schroedinger type equation is given. Explicitly energy dependent
coupled channel potentials, for use in partial wave Schroedinger like
equations, with nonlinear and complicated derivative terms, result. We
developed the necessary numerics and study np and pp scattering phase shifts
for energies 0-3 GeV and the deuteron bound state. The interactions are
inspired by meson exchange of pi, eta, rho,omega and sigma mesons for which we
adjust coupling constants. This yields, in the first instant, high quality fits
to the Arndt phase shifts 0-300 MeV. Second, the potentials show a universal,
independent from angular momentum, core potential which is generated from the
relativistic meson exchange dynamics. Extrapolations towards higher energies,
up to 3 GeV, allow to separate a QCD dominated short range zone as well as
inelastic nucleon excitation mechanism contributing to meson production. A
local and/or nonlocal optical model, in addition to the meson exchange Dirac
potential, produces agreement between theoretical and data phase shifts. Third,
the 1S0, 3P0 and 3P1 partial waves elicit a fusion/scission, for T-Lab<1GeV,
and a fusion/fission, for T-Lab>1 GeV, mechanism for intermediate dibaryon
formation.
