  Quantum mechanics and relativistic causality together imply nonlocality:
nonlocal correlations (that violate the CHSH inequality) and nonlocal equations
of motion (the Aharonov-Bohm effect). Can we invert the logical order? We
consider a conjecture that nonlocality and relativistic causality together
imply quantum mechanics. We show that correlations preserving relativistic
causality can violate the CHSH inequality more strongly than quantum
correlations. Also, we describe nonlocal equations of motion, preserving
relativistic causality, that do not arise in quantum mechanics. In these
nonlocal equations of motion, an experimenter ``jams" nonlocal correlations
between quantum systems.
