In this review I focus on two literature in this broad set of research that are related to two  classic arguments in security studies and show how new modeling techniques have allowed us to build  theories helping us better understand age old questions about the effect of uncertainty on the likelihood of war.    While many issues remain unresolved, these two literature make steps toward explaining different ways uncertainty  can matter for the decision to go to war.  These analyses help us clarify, if not complete answer, questions like: what does it mean for mutual optimism it case war?  How might we incorporate bounded rationality rigorously in our models of choice if we think it is a crucial element linking uncertainty to war?  And how might fear of other's intentions or uncertainty about fundamentals, like the technology of war, led to cascades of fear and spirals of conflictual behavior?