After bringing together independent information on contested territory, rivalries, and conflict escalation (militarized interstate disputes (MIDs) and war), we examine the timing of the temporal ordering of these three processes. Contrary to conventional expectations, we find the contested territory-militarized dispute-rivalry ordering to be rare. Rivalries and contested territory often begin at the same time. Next, after setting up a unified model, we find the triadic combination of contested territory, contiguity, and strategic rivalry to be a strong explanatory combination for MIDs and war over time (1919–1992). We also control for other explanatory factors such as mixed regime type and major power status. These findings provide strong support for arguments such as Vasquez's steps-to-war theory that specify these sources of conflict escalation.