I present a fairly detailed discussion of various contributions to the
anomalous magnetic moment of the muon a_mu. I try to give an unbiased
evaluation of the validity of the SM prediction for this quantity and to point
out some delicate issues involved in its calculation. I conclude that the
theory uncertainties in the SM prediction for the muon anomalous magnetic
moment are underestimated and a great deal of work will be required to reduce
these uncertainties to the level required by experiment.Comment: 12 pages, revte
