Two central concepts of quantum mechanics are Heisenberg's uncertainty principle, and a
subtle form of non-locality that Einstein famously called ''spooky action at a distance''.
These two fundamental features have thus far been distinct concepts. In this talk, we'll
see that they are inextricably and quantitatively linked. Quantum mechanics cannot be
more non-local with measurements that respect the uncertainty principle. In fact, the link
between uncertainty and non-locality holds for all physical theories. More specifically, the
degree of non-locality of any theory is determined by two factors -- the strength of the
uncertainty principle, and the strength of a property called ''steering'', which determines
which states can be prepared at one location given a measurement at another.