  We explore how the IR pathologies of noncommutative field theory are resolved
when the theory is realized as open strings in background B-fields:
essentially, since the IR singularities are induced by UV/IR mixing, string
theory brings them under control in much the same way as it does the UV
singularities. We show that at intermediate scales (where the Seiberg-Witten
limit is a good approximation) the theory reproduces the noncommutative field
theory with all the (un)usual features such as UV/IR mixing, but that outside
this regime, in the deep infra-red, the theory flows continuously to the
commutative theory and normal Wilsonian behaviour is restored. The resulting
low energy physics resembles normal commutative physics, but with additional
suppressed Lorentz violating operators. We also show that the phenomenon of
UV/IR mixing occurs for the graviton as well, with the result that, in
configurations where Planck's constant receives a significant one-loop
correction (for example brane-induced gravity), the distance scale below which
gravity becomes non-Newtonian can be much greater than any compact dimensions.
