We consider heterotic string compactifications to four dimensions when
instantons shrink to zero size. If the standard model gauge group originates
from the new gauge symmetry associated with the small instantons singularity,
then the weakly or strongly coupled heterotic string scales can be taken to be
arbitrarily low. The SO(32) and E_8\times E_8 gauge groups can then be very
weakly coupled even at the string scale and behave as non-abelian global
symmetries. We comment on a possible role of small instantons in supersymmetry
breaking.Comment: 9 pages, Late
