National Institute’s study, The “Action-Reaction” Arms Race Narrative vs. Historical Realities, addresses the resurgent expressions of the “action-reaction” arms race narrative and its corollary “inaction-inaction” narrative. These narratives are the basis for frequent assertions that the United States is to blame for the “arms race” and that if the United States would only stop its nuclear programs, opponents would also stop building their nuclear forces. This argument, which has its roots in the 1960s, has not changed since then and is now leveled at the contemporary and much-delayed U.S. nuclear modernization program. As in the past, the assertion now commonly expressed is that current U.S. efforts to preserve its strategic deterrence forces are the cause of a new action-reaction arms race cycle and should, therefore, be stopped. This study examined numerous inflection points in the development of U.S. strategic policy since the late 1960s, reviewing now-declassified governmental and unclassified non-governmental studies and books, and concludes that history disproves the action-reaction/inaction-inaction narrative.