To help incorporate security into INCOSE’s Systems Engineering Vision 2035, the INCOSE systems security engineering working group endorses a paradigmatic shift to reframe systems security in terms of being trustworthy, loss-driven, and capabilities-based. Similar research out of Organization A has explored cutting-edge approaches to systems security for national security applications. Taken together, these efforts both highlight to need for—and a path toward—a scientific foundation for security. Leveraging underlying tenets of systems theory, observed security heuristics, and the concepts emerging from INCOSE’s SSE working helps triangulate a set of “first principles” as part of a scientific foundation for security consistent with the (often ignored) interactions between physical security designs, cyber security architectures, and personnel security programs. These first principles, in turn, are the basis for a set of derived systems security performance axioms that support current INCOSE SSE working efforts. The logic and designability benefits of this approach is demonstrated with a multilayer network model-based approach for systems security. The structure of this scientific foundation for security offers additional, innovative opportunities to achieve desired levels of trustworthiness, creative mechanisms to meet needs, innovative loss-driven approaches, and enhanced capabilities—all aimed to at producing more efficient and effective systems security solutions against current and emerging threats, uncertainties, and complexities.