  A potential between mesons is extracted from 4-point functions within lattice
gauge theory taking 2+1 dimensional QED as an example. This theory possesses
confinement and dynamical fermions. The resulting meson-meson potential has a
short-ranged hard repulsive core and the expected dipole-dipole forces lead to
attraction at intermediate distances. Sea quarks lead to a softer form of the
total potential.
