Recent research interests have focused on advancing game theory and its applications to cyber systems. Advancement in this line of research may bring insights and new techniques that would help cyber defenders at two distinct levels. In macrolevel strategy, the research would yield a set of guiding principles for cyber operation that can satisfy mission assurance requirements under resource constraint, and under known and assumed threats and attacker capabilities. In micro-level decision support, the research results may point to specifi c actions to deal with real time or near real time threats, in order to defeat ongoing attacks or to prevent future ones. It should be possible to link the two levels (or multi-level) of strategy and decision making.