  The lattice data on the instanton size distribution suggest an additional
O($\rho^2)$ action. The small-$\rho$ effect O($\rho^4)$ predicted by the
Operator Product Expansion (OPE) is not observed. Similar deviations are also
found for non-perturbative response to a small static color dipoles: it is O(r)
not O(r$^2$). We suggest that small instanton radii in the QCD vacuum and small
radii of the QCD strings (to which this observation relates) are consequences
of the same phenomenon: a very robust dual superconductivity in the QCD vacuum,
with relatively large Higgs VEV and surprisingly large Higgs mass.
