We raise the issue whether gauge theories, that are not renormalizable
in the usual power counting sense, are nevertheless renormalizable in
the modern sense that all divergences can be cancelled by renormaliza
tion of the infinite number of terms in the bare action, We find that
a theory is renormalizable in this sense if the a priori constraints t
hat we impose on the form of the bare action correspond to the cohomol
ogy of the BRST-transformations generated by the action. Recent cohomo
logy theorems of Barnich, Brandt, and Henneaux are used to show that c
onventionally nonrenormalizable theories of Yang-Mills fields (such as
quantum chromodynamics with heavy quarks integrated out) and/or gravi
tation are renormalizable in the modem sense.