  It is well known that an identical pair of extremal Reissner-Nordstrom black
holes placed a large distance apart will exert no force on each other. In this
paper, I establish that the same result holds in a very large class of
two-derivative effective theories containing an arbitrary number of gauge
fields and moduli, where the appropriate analog of an extremal
Reissner-Nordstrom black hole is a charged, spherically symmetric black hole
with vanishing surface gravity or vanishing horizon area. Analogous results
hold for black branes.
