  This paper describes my talk given to the 27th Johns Hopkins Workshop:
Symmetries and Mysteries of M Theory, G\"oteborg, Sweden, 24-26 August, 2003.
After a brief introduction to the lightcone worldsheet formalism for summing
the planar diagrams of field theory, I explain how the {\it uv} divergences of
quantum field theory translate to the new language of string. It is shown
through one loop that, at least for scalar cubic vertices, the counter-terms
necessary for Poincar\'e invariance in space-time dimensions $D\leq 6$ are
indeed local on the worldsheet. The extension to cover the case of gauge field
vertices will be more complicated due to the extra divergences at $p^+=0$ in
lightcone gauge.
