In this talk I will outline a construction of the Feynman propagator for the wave equation with an inverse square potential on Minkowski space. The construction relies on a number of techniques in geometric microlocal analysis though I will only be able to describe a few of them. To construct the Feynman propagator we construct appropriate (variable order) weighted Sobolev spaces encoding the Feynman property, then show that a rescaling of the operator is Fredholm on these spaces and invertible for a range of weights. The Fredholm result relies on propagation estimates (proved via microlocal commutator methods) as well as special function analysis (to invert a normal operator at infinity). Because the propagation estimates naturally take place on the level of H^1, we also construct an adapted large pseudodifferential calculus in order to shift the orders.