  The properties of string networks at scales well below the horizon are poorly
understood, but they enter critically into many observables. We argue that in
some regimes, stretching will be the only relevant process governing the
evolution. In this case, the string two-point function is determined up to
normalization: the fractal dimension approaches one at short distance, but the
rate of approach is characterized by an exponent that plays an essential role
in network properties. The smoothness at short distance implies, for example,
that cosmic string lensing images are little distorted. We then add in loop
production as a perturbation and find that it diverges at small scales. This
need not invalidate the stretching model, since the loop production occurs in
localized regions, but it implies a complicated fragmentation process. Our
ability to model this process is limited, but we argue that loop production
peaks a few orders of magnitude below the horizon scale, without the inclusion
of gravitational radiation. We find agreement with some features of
simulations, and interesting discrepancies that must be resolved by future
work.
