  The recently observed long-range coherent structure of topological charge
fluctuations in QCD is compared with theoretical expectations based on the
AdS/CFT brane construction of nonsupersymmetric gauge theory by Witten. Similar
observations of coherent topologicalcharge structure in 2D $CP^{N-1}$ sigma
models are interpreted in terms of Wilson lines representing world lines of
screened electric charges. The analogy between 2D U(1) and 4D Yang-Mills theory
leads to the interpretation of the observed coherent sheets of topological
charge in QCD as screened ``Wilson bags'' first suggested by Luscher. The
duality between the Wilson bag surface and a wrapped 6-brane in IIA string
theory is discussed. The complete screening of the force between bag surfaces
for integer values of the bag charge $\theta/2\pi$ corresponds to the
observation by Polchinski that the net force between d-branes from closed
string exchange vanishes for quantized values of Ramond-Ramond charge.
