  We consider the version of QCD in Euclidean Landau gauge in which the
restriction to the Gribov region is implemented by a local, renormalizable
action. This action depends on the Gribov parameter $\gamma$, with dimensions
of (mass)$^4$, whose value is fixed in terms of $\Lambda_{QCD}$, by the gap
equation, known as the horizon condition, ${\p \Gamma \over \p \gamma} = 0$,
where $\Gamma$ is the quantum effective action. The restriction to the Gribov
region suppresses gluons in the infrared, which nicely explains why gluons are
not in the physical spectrum, but this only makes makes more mysterious the
origin of the long-range force between quarks. In the present article we
exhibit the symmetries of $\Gamma$, and show that the solution to the gap
equation, which defines the classical vacuum, spontaneously breaks some of the
symmetries $\Gamma$. This implies the existence of massless Goldstone bosons
and fermions that do not appear in the physical spectrum. Some of the Goldstone
bosons may be exchanged between quarks, and are candidates for a long-range
confining force. As an exact result we also find that in the infrared limit the
gluon propagator vanishes like $k^2$.
