  Although the Aharonov-Bohm and related effects are familiar in solid state
and high energy physics, the nonlocality of these effects has been questioned.
Here we show, for the first time, that the Aharonov-Bohm effect has two very
different aspects. One aspect is instantaneous and nonlocal; the other aspect,
which depends on entanglement, unfolds continuously over time. While local,
gauge-invariant variables may occasionally suffice for explaining the
continuous aspect, we argue that they cannot explain the instantaneous aspect.
Thus the Aharonov-Bohm effect is, in general, nonlocal.
