Two topics in QCD spin

After a general introduction to QCD spin physics and nucleon spin decomposition, I will talk about two recent developments in this field. First, I discuss a novel connection between the nucleon electric dipole moment (EDM) and polarized Deep Inelastic Scattering (DIS). I argue that the matrix element of the CP-violating Weinberg operator is related to certain higher-order corrections in polarized DIS. Second, I discuss the small-x behavior of polarized parton distribution functions and orbital angular momentum distributions within the framework of double logarithmic resummation in QCD.