  We show that, within the Quasiparticle Random Phase Approximation (QRPA) and
the renormalized QRPA (RQRPA) based on the Bonn CD nucleon-nucleon interaction,
the competition between the pairing and the neutron-proton particle-particle
and particle-hole interactions causes contributions to the neutrinoless
double-beta decay matrix element to nearly vanish at internucleon distances of
more than 2 or 3 fermis. As a result, the matrix element is more sensitive to
short-range/high-momentum physics than one naively expects. We analyze various
ways of treating that physics and quantify the uncertainty it produces in the
matrix elements, with three different treatments of short-range correlations.
