  We develop a fully fledged theory of quantum dynamical patterns of behavior
that are nonlocally induced. To this end we generalize the standard
Laplacian-based framework of the Schr\"{o}dinger picture quantum evolution to
that employing nonlocal (pseudodifferential) operators. Special attention is
paid to the Salpeter (here, $m\geq 0$) quasirelativistic equation and the
evolution of various wave packets, in particular to their radial expansion in
3D. Foldy's synthesis of "covariant particle equations" is extended to
encompass free Maxwell theory, which however is devoid of any "particle"
content. Links with the photon wave mechanics are explored.
