  It is pointed out that the space noncommutativity parameters $theta^{\mu
\nu}$ in noncommutative gauge theory can be considered as a set of
superselection parameters, in analogy with the theta-angle in ordinary gauge
theories. As such, they do not need to enter explicitly into the action. A
simple generic formula is then suggested to reproduce the Chern-Simons action
in noncommutative gauge theory, which reduces to the standard action in the
commutative limit but in general implies a cascade of lower-dimensional
Chern-Simons terms. The presence of these terms in general alters the vacuum
structure of the theory and nonstandard gauge theories can emerge around the
new vacua.
