In this proposal, we will outline a broad research plan for the utilization of methods from operator theory, dilation theory, and interpolation theory to study a number of issues in robust control and nonlinear systems design. We will be particularly interested in extending the $H^infty$ control methodology to nonlinear systems in order to find an applicable nonlinear robust synthesis theory. We will also discuss further extensions of our to $mu$-synthesis as well as distributed $H^infty$ control.