  Quantum weakdynamics (QWD) as an SU(3)_I gauge theory with the Theta vacuum
term is considered to be the unification of the electroweak interaction as an
SU(2)_L x U(1)_Y gauge theory. The grand unification of SU(3)_I x SU(3)_C
beyond the standard model SU(3)_C x SU(2)_L x U(1)_Y is established by the
group SU(3)_I. The grand unified interactions break down to weak and strong
interactions at a new grand unification scale 10^{3} GeV, through dynamical
spontaneous symmetry breaking (DSSB); the weak and strong coupling constants
are the same, alpha_i = alpha_s ~ 0.12, at this scale. DSSB is realized by the
condensation of scalar fields, postulated to be spatially longitudinal
components of gauge bosons, instead of Higgs particles. Quark and lepton family
generation, the Weinberg angle sin^2 theta_W = 1/4, and the Cabbibo angle sin
theta_C = 1/4 are predicted. The electroweak coupling constants are alpha_z =
alpha_i/3, alpha_w = alpha_i/4, alpha_y = alpha_i/12, and alpha_e = alpha_i/16
= 1/137; there are symmetric isospin interactions.
