  The scale of a phenomenologically successful charge-symmetry-violating
nucleon-nucleon interaction, that attributed to meson exchange with a $\Delta I
=1$ rho-omega transition, is set by the Coleman-Glashow SU(2) breaking tadpole
mechanism. A single tadpole scale has been obtained from symmetry arguments,
electromagnetic meson and baryon measured mass splittings, and the observed
isospin violating ($\Delta I=1$) decay $\omega \to \pi^+\pi^-$. The hadronic
realization of this tadpole mechanism lies in the $I = 1$ $a_0$ scalar meson.
We show that measured hadronic and two-photon widths of the $a_0$ meson, with
the aid of the Vector Meson Dominance model, recover the universal
Coleman-Glashow tadpole scale.
