Several esteemed scholars argue that Russia is highly unlikely to conceal an “escalate to de-escalate” nuclear strategy, which would have Russian forces use limited nuclear strikes to end a conventional war Russia is losing. Doing so, they argue, would forfeit the strategy’s deterrent effect. They are right that hiding a strategy of nuclear de-escalation may sacrifice some deterrent effects, at least in peacetime. But it is equally true that concealing it may allow Russia to achieve greater deterrent effects once a conflict arises. Concealing an “escalate to de-escalate” strategy would also allow Russia to complicate U.S. and NATO policymaking more than revealing it. Finally, even if Russia doesn’t have a classified doctrine authorizing nuclear de-escalation, Moscow might still attempt to “escalate to de-escalate” in a confrontation. Logic would seem to suggest that revealing an “escalate to de-escalate” strategy would maximize its deterrent effect – but that depends on the type and timing of deterrent effect the Kremlin prioritizes. For instance, Russian policymakers may believe that revealing this strategy in peacetime would dull its psychological effects in a crisis or conflict by giving U.S. and NATO policymakers and populations time to mentally acclimate to its existence. Conversely, the Kremlin may believe that revealing a strategy of nuclear de-escalation at the outset of a conflict – or at a critical juncture therein – would maximize its psychological impact, and therefore, its deterrent effect, in a crisis or conflict. This might well be true, especially if it occurs when NATO is divided over whether or not to go to war, certain members in the Alliance are more afraid of nuclear escalation than others, and civilian populations across NATO are already frightened by the possibility of war, much less nuclear war. Russian officials might also fear that announcing an “escalate to de-escalate” strategy during peacetime would trigger Western countermeasures. If this was their concern, then ambiguity has not been as successful as they might have liked, inasmuch as the 2018 Nuclear Posture Review explicitly prioritizes development of countermeasures for a Russian strategy of nuclear de-escalation. Even so, one might argue, Russia’s announcement of such a strategy could still trigger even harsher or accelerated responses. By the same token, Russian officials may recognize that retaining ambiguity complicates U.S. and NATO planning, procurement, and alliance management more than revealing an “escalate to de-escalate” strategy. If Russia announced this strategy, it might reasonably expect the United States and European allies to unite more readily around a set of strong responses. By not doing so, it leaves those fissures open, fueling some Europeans’ fears that the United States is nuclear warmongering, and injecting further dysfunction into the NATO planning process. Similar can be said about Russian ambiguity’s effects in the United States itself. Even if Russia has adopted this strategy, by not announcing it, it injects discord into the U.S. defense planning and budgetary processes. Among other things, this forces the U.S. Defense Department to expend more political capital to secure funding for certain aspects of nuclear modernization than it might otherwise have had to if Moscow announced its nuclear intent. It is therefore at least logical that Russia might conceal a doctrine authorizing nuclear de-escalation. At the same time, however, it is still entirely plausible that Russia doesn’t have a classified doctrine authorizing nuclear de-escalation. The unclassified evidence does not point conclusively in one direction or the other. That said, even if Russia doesn’t have a classified doctrine of nuclear de-escalation, it shouldn’t give Western policymakers or analysts too much reassurance. That’s because even Russian leaders themselves probably can’t know if they’d actually attempt nuclear de-escalation in a conflict, whatever their doctrine says. Any doctrine – concealed or revealed – is not determinative. It is prescriptive. So even if Russia does have a doctrine of “escalate to de-escalate,” it doesn’t necessarily mean that a Russian leader would attempt nuclear de-escalation in a conflict. The converse is also true. Even if Russia hasn’t adopted an “escalate to de-escalate” nuclear strategy, that by no means proves that they wouldn’t attempt nuclear de-escalation anyway (bearing in mind that they have the capability to do so). Doctrine is an important tool for evaluating how an adversary might behave under certain circumstances. But its utility must not be overstated. Evaluated alongside official rhetoric, authoritative writings, military exercises, force structure, and other data, doctrine can tell us much about how Russian leaders might weigh different options for use in a crisis or conflict. For that reason, it is important not to discount the real possibility that classified documents might well authorize Russian use of limited nuclear strikes for de-escalatory purposes. At the same time, however, neither doctrine nor any of these other sources can offer true certainty about how any adversary will behave when all is on the line. The United States’ evolving response to Russia’s nuclear strategy should reflect that uncertainty by taking steps designed to deter Russian limited nuclear use without backing Russian policymakers into a corner such that they think they have no other option. Fortunately, the 2018 Nuclear Posture Review does just that by calling for modest improvements to America’s ability to deter limited nuclear war. This creates space for Washington to engage Moscow in pursuit of non-military opportunities to further decrease likelihood of Russian resort to nuclear de-escalation in a future confrontation. Alexander Velez-Green is a research associate at the Center for a New American Security and a member of the CSIS PONI Nuclear Scholars Initiative. His research focuses on Russian views of deterrence, escalation management, and strategic stability.