  There is a good deal of current interest in the condensate A^2 which has been
seen to play an important role in calculations which make use of the operator
product expansion. That development has led to the publication of a large
number of papers which discuss how that condensate could play a role in a
gauge-invariant formulation. In the present work we consider gluon propagation
in the presence of such a condensate which we assume to be present in the
vacuum. We show that the gluon propagator has no on-mass-shell pole and,
therefore, a gluon cannot propagate over extended distances. That is, the gluon
is a nonpropagating mode in the gluon condensate. In the present work we
discuss the properties of both the Euclidean-space and Minkowski-space gluon
propagator. In the case of the Euclidean-space propagator we can make contact
with the results of QCD lattice calculations of the propagator in the Landau
gauge. With an appropriate choice of normalization constants, we present a
unified representation of the gluon propagator that describes both the
Minkowski-space and Euclidean-space dynamics in which the A^2 condensate plays
an important role.
