Cognitive radar has emerged as key enabling technology to meet the demands of ever increasingly complex and congested radio frequency (RF) operating environments. The generally non-stationary, heterogeneous, and time-varying nature of the modern RF environment all but precludes the use of traditional adaptive processing methods that require the existence of wide sense stationary (WSS) training data. This necessitates an advanced modeling & simulation (M&S) framework that captures much of the real-world physics that gives rise to the aforementioned challenges such as heterogenous clutter, dense background targets, and intentional/unintentional radio frequency interference (RFI). As part of this demonstration, several examples that capture all these effects will be presented using the high-fidelity RF M&S tool RFView.