  We consider contributions to the rare decay K+ -> pi+ nu nubar which become
nonlocal at the charm scale. Compared to the leading term, such amplitudes are
suppressed by two powers of mK/mc and could potentially give corrections at the
level of 15%. We compute the leading coefficients of the subleading dimension
eight operators in the effective theory below the charm mass. The matrix
elements of these operators cannot all be calculated from first principles and
some must be modeled. We find that these contributions are likely to be small,
but the estimate is sufficiently uncertain that the result may be as large as
the existing theoretical uncertainty from other sources.
